diff --git a/selfdrive/ui/layouts/home.py b/selfdrive/ui/layouts/home.py
index c759346f6..2c06190b3 100644
--- a/selfdrive/ui/layouts/home.py
+++ b/selfdrive/ui/layouts/home.py
@@ -2,7 +2,6 @@ import time
 import pyray as rl
 from collections.abc import Callable
 from enum import IntEnum
-from openpilot.common.params import Params
 from openpilot.selfdrive.ui.ui_state import ui_state
 from openpilot.selfdrive.ui.widgets.offroad_alerts import UpdateAlert, OffroadAlert
 from openpilot.selfdrive.ui.widgets.exp_mode_button import ExperimentalModeButton
@@ -32,7 +31,7 @@ class HomeLayoutState(IntEnum):
 class HomeLayout(Widget):
   def __init__(self):
     super().__init__()
-    self.params = Params()
+    self.params = ui_state.ui_params
 
     self.update_alert = UpdateAlert()
     self.offroad_alert = OffroadAlert()
diff --git a/selfdrive/ui/layouts/main.py b/selfdrive/ui/layouts/main.py
index 9aa8e363c..bd24381a4 100644
--- a/selfdrive/ui/layouts/main.py
+++ b/selfdrive/ui/layouts/main.py
@@ -47,6 +47,11 @@ class MainLayout(Widget):
       if not self._onboarding_window.completed:
         gui_app.push_widget(self._onboarding_window)
 
+    # TICI/TIZI offroad views are mostly static. Keep onroad and interaction
+    # at the normal rate, but avoid spending GPU/CPU budget redrawing idle UI.
+    # MainLayout is only used by BIG UI, so MICI retains its existing scheduler.
+    gui_app.configure_adaptive_rendering(gui_app.big_ui())
+
   @staticmethod
   def _critical_full_alert_active() -> bool:
     if not ui_state.sm.recv_frame['selfdriveState']:
@@ -60,6 +65,7 @@ class MainLayout(Widget):
       return
 
     self._handle_onroad_transition()
+    gui_app.set_render_mode(self._current_mode == MainState.ONROAD or ui_state.started)
     self._render_main_content()
 
   def _setup_callbacks(self):
@@ -105,11 +111,13 @@ class MainLayout(Widget):
       self._layouts[self._current_mode].hide_event()
       self._current_mode = layout
       self._layouts[self._current_mode].show_event()
+      gui_app.request_high_fps()
 
   def open_settings(self, panel_type: PanelType):
     self._layouts[MainState.SETTINGS].set_current_panel(panel_type)
     self._set_current_layout(MainState.SETTINGS)
     self._sidebar.set_visible(False)
+    gui_app.request_high_fps()
 
   def _on_settings_clicked(self):
     self.open_settings(PanelType.STARPILOT)
diff --git a/selfdrive/ui/layouts/settings/common.py b/selfdrive/ui/layouts/settings/common.py
index 5e87a6447..2066ec5b7 100644
--- a/selfdrive/ui/layouts/settings/common.py
+++ b/selfdrive/ui/layouts/settings/common.py
@@ -2,4 +2,4 @@ from openpilot.selfdrive.ui.ui_state import ui_state
 
 
 def restart_needed_callback(_):
-  ui_state.params.put_bool("OnroadCycleRequested", True)
+  ui_state.ui_params.put_bool("OnroadCycleRequested", True)
diff --git a/selfdrive/ui/layouts/settings/device.py b/selfdrive/ui/layouts/settings/device.py
index dc9a6c3fe..96ec6e8df 100644
--- a/selfdrive/ui/layouts/settings/device.py
+++ b/selfdrive/ui/layouts/settings/device.py
@@ -11,7 +11,6 @@ import pyray as rl
 import qrcode
 
 from openpilot.common.basedir import BASEDIR
-from openpilot.common.params import Params
 from openpilot.common.swaglog import cloudlog
 from openpilot.selfdrive.ui.onroad.driver_camera_dialog import DriverCameraDialog
 from openpilot.selfdrive.ui.ui_state import ui_state
@@ -112,7 +111,7 @@ class DeviceLayout(Widget):
   def __init__(self):
     super().__init__()
 
-    self._params = Params()
+    self._params = ui_state.ui_params
     self._select_language_dialog: MultiOptionDialog | None = None
     self._driver_camera: DriverCameraDialog | None = None
     self._pair_device_dialog: PairingDialog | None = None
diff --git a/selfdrive/ui/layouts/settings/software.py b/selfdrive/ui/layouts/settings/software.py
index 2e5d3e601..b4705502e 100644
--- a/selfdrive/ui/layouts/settings/software.py
+++ b/selfdrive/ui/layouts/settings/software.py
@@ -106,11 +106,11 @@ class SoftwareLayout(Widget):
     super().__init__()
 
     self._onroad_label = ListItem(lambda: tr("Updates are only downloaded while the car is off."))
-    self._version_item = text_item(lambda: tr("Current Version"), starpilot_display_description(ui_state.params.get("UpdaterCurrentDescription")))
+    self._version_item = text_item(lambda: tr("Current Version"), starpilot_display_description(ui_state.ui_params.get("UpdaterCurrentDescription")))
     self._auto_updates_toggle = toggle_item(
       lambda: tr("Automatically Install Updates"),
       lambda: tr("Automatically install updates when parked with an active internet connection."),
-      initial_state=ui_state.params.get_bool("AutomaticUpdates"),
+      initial_state=ui_state.ui_params.get_bool("AutomaticUpdates"),
       callback=self._on_auto_updates_toggle,
     )
     self._download_btn = button_item(
@@ -129,8 +129,8 @@ class SoftwareLayout(Widget):
 
     # Branch switcher
     self._branch_btn = button_item(lambda: tr("Target Branch"), lambda: tr("SELECT"), callback=self._on_select_branch)
-    self._branch_btn.set_visible(not ui_state.params.get_bool("IsTestedBranch"))
-    self._branch_btn.action_item.set_value(ui_state.params.get("UpdaterTargetBranch") or "")
+    self._branch_btn.set_visible(not ui_state.ui_params.get_bool("IsTestedBranch"))
+    self._branch_btn.action_item.set_value(ui_state.ui_params.get("UpdaterTargetBranch") or "")
     self._branch_dialog: MultiOptionDialog | None = None
 
     self._scroller = Scroller(
@@ -159,11 +159,11 @@ class SoftwareLayout(Widget):
     self._onroad_label.set_visible(ui_state.is_onroad())
 
     # Update current version and release notes
-    current_desc = starpilot_display_description(ui_state.params.get("UpdaterCurrentDescription"))
-    current_release_notes = (ui_state.params.get("UpdaterCurrentReleaseNotes") or b"").decode("utf-8", "replace")
+    current_desc = starpilot_display_description(ui_state.ui_params.get("UpdaterCurrentDescription"))
+    current_release_notes = (ui_state.ui_params.get("UpdaterCurrentReleaseNotes") or b"").decode("utf-8", "replace")
     self._version_item.action_item.set_text(current_desc)
     self._version_item.set_description(current_release_notes)
-    self._auto_updates_toggle.action_item.set_state(ui_state.params.get_bool("AutomaticUpdates"))
+    self._auto_updates_toggle.action_item.set_state(ui_state.ui_params.get_bool("AutomaticUpdates"))
 
     # Update download button visibility and state
     self._download_btn.set_visible(ui_state.is_offroad())
@@ -185,10 +185,10 @@ class SoftwareLayout(Widget):
 
     # ── Normal updater state (only when fast update NOT active) ───
     if state.stage == FastUpdateStage.IDLE:
-      updater_state = ui_state.params.get("UpdaterState") or "idle"
-      failed_count = ui_state.params.get("UpdateFailedCount") or 0
-      fetch_available = ui_state.params.get_bool("UpdaterFetchAvailable")
-      update_available = ui_state.params.get_bool("UpdateAvailable")
+      updater_state = ui_state.ui_params.get("UpdaterState") or "idle"
+      failed_count = ui_state.ui_params.get("UpdateFailedCount") or 0
+      fetch_available = ui_state.ui_params.get_bool("UpdaterFetchAvailable")
+      update_available = ui_state.ui_params.get_bool("UpdateAvailable")
 
       if updater_state != "idle":
         self._waiting_for_updater = False
@@ -203,7 +203,7 @@ class SoftwareLayout(Widget):
           self._download_btn.action_item.set_value(tr("update available"))
           self._download_btn.action_item.set_text(tr("DOWNLOAD"))
         else:
-          last_update = ui_state.params.get("LastUpdateTime")
+          last_update = ui_state.ui_params.get("LastUpdateTime")
           if last_update:
             formatted = time_ago(last_update)
             self._download_btn.action_item.set_value(tr("up to date, last checked {}").format(formatted))
@@ -219,14 +219,14 @@ class SoftwareLayout(Widget):
       update_available = False
 
     # Update target branch button value
-    current_branch = ui_state.params.get("UpdaterTargetBranch") or ""
+    current_branch = ui_state.ui_params.get("UpdaterTargetBranch") or ""
     self._branch_btn.action_item.set_value(current_branch)
 
     # Update install button
     self._install_btn.set_visible(ui_state.is_offroad() and update_available and state.stage == FastUpdateStage.IDLE)
     if update_available and state.stage == FastUpdateStage.IDLE:
-      new_desc = starpilot_display_description(ui_state.params.get("UpdaterNewDescription"))
-      new_release_notes = (ui_state.params.get("UpdaterNewReleaseNotes") or b"").decode("utf-8", "replace")
+      new_desc = starpilot_display_description(ui_state.ui_params.get("UpdaterNewDescription"))
+      new_release_notes = (ui_state.ui_params.get("UpdaterNewReleaseNotes") or b"").decode("utf-8", "replace")
       self._install_btn.action_item.set_text(tr("INSTALL"))
       self._install_btn.action_item.set_value(new_desc)
       self._install_btn.set_description(new_release_notes)
@@ -327,7 +327,7 @@ class SoftwareLayout(Widget):
     threading.Thread(target=_run_worker, daemon=True).start()
 
   def _on_auto_updates_toggle(self, enabled: bool):
-    ui_state.params.put_bool("AutomaticUpdates", enabled)
+    ui_state.ui_params.put_bool("AutomaticUpdates", enabled)
 
   def _on_uninstall(self):
     def handle_step1(result):
@@ -338,13 +338,13 @@ class SoftwareLayout(Widget):
 
             def handle_step3(result3):
               if result3 == DialogResult.CONFIRM:
-                ui_state.params.clear_all()
-              ui_state.params.put_bool("DoUninstall", True)
+                ui_state.ui_params.clear_all()
+              ui_state.ui_params.put_bool("DoUninstall", True)
 
             dialog = ConfirmDialog(tr("This is a complete factory reset and cannot be undone. Are you absolutely sure?"), tr("Reset"), callback=handle_step3)
             gui_app.push_widget(dialog)
           else:
-            ui_state.params.put_bool("DoUninstall", True)
+            ui_state.ui_params.put_bool("DoUninstall", True)
 
         dialog = ConfirmDialog(
           tr("Do you want to perform a full factory reset? All saved assets and settings will be permanently deleted!"), tr("Factory Reset"), tr("Skip"), callback=handle_step2
@@ -364,12 +364,12 @@ class SoftwareLayout(Widget):
   def _on_install_update(self):
     # Trigger reboot to install update
     self._install_btn.action_item.set_enabled(False)
-    ui_state.params.put_bool("DoReboot", True)
+    ui_state.ui_params.put_bool("DoReboot", True)
 
   def _on_select_branch(self):
     # Get available branches and order
-    current_git_branch = ui_state.params.get("GitBranch") or ""
-    branches_str = ui_state.params.get("UpdaterAvailableBranches") or ""
+    current_git_branch = ui_state.ui_params.get("GitBranch") or ""
+    branches_str = ui_state.ui_params.get("UpdaterAvailableBranches") or ""
     branches = [b for b in branches_str.split(",") if b]
 
     for b in [current_git_branch, "devel-staging", "devel", "nightly", "nightly-dev", "master"]:
@@ -377,13 +377,13 @@ class SoftwareLayout(Widget):
         branches.remove(b)
         branches.insert(0, b)
 
-    current_target = ui_state.params.get("UpdaterTargetBranch") or ""
+    current_target = ui_state.ui_params.get("UpdaterTargetBranch") or ""
 
     def handle_selection(result):
       # Confirmed selection
       if result == DialogResult.CONFIRM and self._branch_dialog is not None and self._branch_dialog.selection:
         selection = self._branch_dialog.selection
-        ui_state.params.put("UpdaterTargetBranch", selection)
+        ui_state.ui_params.put("UpdaterTargetBranch", selection)
         self._branch_btn.action_item.set_value(selection)
         os.system("pkill -SIGUSR1 -f system.updated.updated")
       self._branch_dialog = None
diff --git a/selfdrive/ui/layouts/settings/starpilot/aethergrid.py b/selfdrive/ui/layouts/settings/starpilot/aethergrid.py
index bb8f0486e..99a4fd46b 100644
--- a/selfdrive/ui/layouts/settings/starpilot/aethergrid.py
+++ b/selfdrive/ui/layouts/settings/starpilot/aethergrid.py
@@ -13,6 +13,7 @@ from openpilot.system.ui.widgets import Widget, DialogResult
 from openpilot.system.ui.widgets.label import gui_label
 
 from openpilot.selfdrive.ui.layouts.settings.starpilot.scribble import draw_custom_icon
+from openpilot.selfdrive.ui.lib.ui_param_cache import shared_ui_params
 
 
 GEOMETRY_OFFSET = 10
@@ -3538,8 +3539,7 @@ class AetherCategoryDrawer(AetherSettingsView):
     
     # Read driving side dynamically for ergonomic layout (LHD vs RHD)
     try:
-      from openpilot.common.params import Params
-      self._is_rhd = Params().get_bool("IsRHD")
+      self._is_rhd = shared_ui_params().get_bool("IsRHD")
     except Exception:
       self._is_rhd = False
 
@@ -5476,4 +5476,3 @@ class TileGrid(Widget):
 
 
 
-
diff --git a/selfdrive/ui/layouts/settings/starpilot/panel.py b/selfdrive/ui/layouts/settings/starpilot/panel.py
index e377dc64b..1568ad694 100644
--- a/selfdrive/ui/layouts/settings/starpilot/panel.py
+++ b/selfdrive/ui/layouts/settings/starpilot/panel.py
@@ -6,6 +6,7 @@ from enum import IntEnum
 import pyray as rl
 
 from openpilot.common.params import Params
+from openpilot.selfdrive.ui.lib.ui_param_cache import shared_ui_params
 from openpilot.starpilot.common.starpilot_variables import update_starpilot_toggles
 from openpilot.system.ui.lib.multilang import tr
 from openpilot.system.ui.lib.application import gui_app
@@ -13,75 +14,50 @@ from openpilot.system.ui.widgets import DialogResult, Widget
 from openpilot.system.ui.widgets.option_dialog import MultiOptionDialog
 from openpilot.selfdrive.ui.layouts.settings.starpilot.aethergrid import TileGrid, HubTile, ToggleTile, ValueTile, SliderTile, SPACING, AetherSliderDialog, AetherListColors
 from openpilot.selfdrive.ui.layouts.settings.starpilot.sectioned_panel import SectionedTileLayout, TileSection
-import time
 
 
 class FrameCachedParams:
   def __init__(self):
-    self._params = Params()
-    self._cache = {}
-    self._last_frame_time = 0.0
-
-  def _check_clear_cache(self):
-    now = time.monotonic()
-    if now != self._last_frame_time:
-      self._cache.clear()
-      self._last_frame_time = now
+    self._cache = shared_ui_params()
 
   def get(self, key, **kwargs):
-    self._check_clear_cache()
-    cache_key = (key, "get", tuple(kwargs.items()))
-    if cache_key not in self._cache:
-      self._cache[cache_key] = self._params.get(key, **kwargs)
-    return self._cache[cache_key]
+    return self._cache.get(key, **kwargs)
 
   def get_bool(self, key, **kwargs):
-    self._check_clear_cache()
-    cache_key = (key, "get_bool", tuple(kwargs.items()))
-    if cache_key not in self._cache:
-      self._cache[cache_key] = self._params.get_bool(key, **kwargs)
-    return self._cache[cache_key]
+    return self._cache.get_bool(key, **kwargs)
 
   def get_int(self, key, **kwargs):
-    self._check_clear_cache()
-    cache_key = (key, "get_int", tuple(kwargs.items()))
-    if cache_key not in self._cache:
-      self._cache[cache_key] = self._params.get_int(key, **kwargs)
-    return self._cache[cache_key]
+    return self._cache.get_int(key, **kwargs)
 
   def get_float(self, key, **kwargs):
-    self._check_clear_cache()
-    cache_key = (key, "get_float", tuple(kwargs.items()))
-    if cache_key not in self._cache:
-      self._cache[cache_key] = self._params.get_float(key, **kwargs)
-    return self._cache[cache_key]
+    return self._cache.get_float(key, **kwargs)
 
   def _notify_changed(self):
-    self._cache.clear()
+    self._cache.invalidate()
     update_starpilot_toggles()
 
   def put(self, key, val, **kwargs):
-    self._params.put(key, val, **kwargs)
+    self._cache.put(key, val, **kwargs)
     self._notify_changed()
 
   def put_bool(self, key, val, **kwargs):
-    self._params.put_bool(key, val, **kwargs)
+    self._cache.put_bool(key, val, **kwargs)
     self._notify_changed()
 
   def put_int(self, key, val, **kwargs):
-    self._params.put_int(key, val, **kwargs)
+    self._cache.put_int(key, val, **kwargs)
     self._notify_changed()
 
   def put_float(self, key, val, **kwargs):
-    self._params.put_float(key, val, **kwargs)
+    self._cache.put_float(key, val, **kwargs)
     self._notify_changed()
 
   def remove(self, key):
-    self._params.remove(key)
+    self._cache.remove(key)
     self._notify_changed()
 
   def __getattr__(self, name):
-    return getattr(self._params, name)
+    return getattr(self._cache, name)
 
 
 class StarPilotPanelType(IntEnum):
diff --git a/selfdrive/ui/layouts/settings/starpilot/scribble.py b/selfdrive/ui/layouts/settings/starpilot/scribble.py
index aa9e16653..6325297ee 100644
--- a/selfdrive/ui/layouts/settings/starpilot/scribble.py
+++ b/selfdrive/ui/layouts/settings/starpilot/scribble.py
@@ -1,9 +1,10 @@
 from __future__ import annotations
 import math
 import pyray as rl
+from openpilot.system.ui.lib.application import gui_app
 
 
-def draw_custom_icon(key: str, x: float, y: float, s: float, color: rl.Color):
+def _draw_custom_icon_geometry(key: str, x: float, y: float, s: float, color: rl.Color):
 
   # Helper for drawing quadratic Bezier curves
   def draw_bezier(p0: rl.Vector2, p1: rl.Vector2, p2: rl.Vector2, thick: float):
@@ -425,4 +426,43 @@ def draw_custom_icon(key: str, x: float, y: float, s: float, color: rl.Color):
     rl.draw_line_ex(rl.Vector2(x_c - 6.5 * s, y_c + 2.5 * s), rl.Vector2(x_c + 6.5 * s, y_c + 2.5 * s), 3.5 * s, color)
 
 
+def draw_custom_icon(key: str, x: float, y: float, s: float, color: rl.Color):
+  """Draw a custom icon, caching its static vector geometry on the GPU."""
+  cache = getattr(gui_app, "cached_render_texture", None)
+  if hasattr(color, "r"):
+    color_key = (color.r, color.g, color.b, color.a)
+  else:
+    components = tuple(color)
+    color_key = (*components[:3], components[3] if len(components) > 3 else 255)
+  if cache is None:
+    _draw_custom_icon_geometry(key, x, y, s, color)
+    return
 
+  # A few strokes extend beyond the authored 60x60 canvas. Padding prevents
+  # those edges from being clipped by the render texture.
+  padding = max(1, int(math.ceil(3.0 * s)))
+  icon_size = max(1, int(round(60.0 * s)))
+  width = icon_size + 2 * padding
+  height = width
+  cache_key = f"aethergrid-icon:{key}:{round(s, 4)}:{width}:{height}:{color_key}"
+  texture = cache(cache_key, width, height,
+                  lambda: _draw_custom_icon_geometry(key, padding, padding, s, color))
+  if texture is None:
+    _draw_custom_icon_geometry(key, x, y, s, color)
+    return
+
+  # Render targets contain premultiplied alpha after drawing onto transparent
+  # black. Use the matching blend mode to avoid applying translucent icon
+  # alpha twice when compositing the cached texture.
+  rl.begin_blend_mode(rl.BlendMode.BLEND_ALPHA_PREMULTIPLY)
+  try:
+    rl.draw_texture_pro(
+      texture,
+      rl.Rectangle(0, 0, width, -height),
+      rl.Rectangle(x - padding, y - padding, width, height),
+      rl.Vector2(0, 0),
+      0.0,
+      rl.WHITE,
+    )
+  finally:
+    rl.end_blend_mode()
diff --git a/selfdrive/ui/layouts/settings/toggles.py b/selfdrive/ui/layouts/settings/toggles.py
index 08800c698..5380960a8 100644
--- a/selfdrive/ui/layouts/settings/toggles.py
+++ b/selfdrive/ui/layouts/settings/toggles.py
@@ -1,5 +1,5 @@
 from cereal import log
-from openpilot.common.params import Params, UnknownKeyName
+from openpilot.common.params import UnknownKeyName
 from openpilot.system.ui.widgets import Widget
 from openpilot.system.ui.widgets.list_view import multiple_button_item, toggle_item
 from openpilot.system.ui.widgets.scroller_tici import Scroller
@@ -38,7 +38,7 @@ DESCRIPTIONS = {
 class TogglesLayout(Widget):
   def __init__(self):
     super().__init__()
-    self._params = Params()
+    self._params = ui_state.ui_params
     self._sync_rhd_toggle()
 
     # param, title, desc, icon, needs_restart
diff --git a/selfdrive/ui/lib/ui_param_cache.py b/selfdrive/ui/lib/ui_param_cache.py
new file mode 100644
index 000000000..9324fe9ef
--- /dev/null
+++ b/selfdrive/ui/lib/ui_param_cache.py
@@ -0,0 +1,107 @@
+"""Small, shared cache for read-mostly UI parameters.
+
+Parameter reads are file-backed.  The BIG UI asks for the same values from
+multiple widgets during a frame, so a short cache avoids repeated open/read/
+close cycles without making settings changes sticky: every write invalidates
+the affected key immediately and the short TTL bounds visibility of writes
+from other processes.
+"""
+
+from __future__ import annotations
+
+import time
+from collections.abc import Callable
+from typing import Any
+
+from openpilot.common.params import Params
+
+
+class UIParamCache:
+  def __init__(self, params: Params | Any | None = None, ttl: float = 0.1,
+               clock: Callable[[], float] = time.monotonic):
+    self._params = params if params is not None else Params()
+    self._ttl = max(0.0, ttl)
+    self._clock = clock
+    self._cache: dict[tuple[Any, ...], tuple[float, Any]] = {}
+
+  @staticmethod
+  def _cache_key(method: str, key: str, args: tuple[Any, ...], kwargs: dict[str, Any]) -> tuple[Any, ...]:
+    # Params arguments are primitive values in UI call sites. repr keeps this
+    # robust for an occasional list/dict default without requiring hashability.
+    return (method, key, repr(args), repr(sorted(kwargs.items())))
+
+  def _read(self, method: str, key: str, *args: Any, **kwargs: Any) -> Any:
+    cache_key = self._cache_key(method, key, args, kwargs)
+    now = self._clock()
+    cached = self._cache.get(cache_key)
+    if cached is not None and now - cached[0] < self._ttl:
+      return cached[1]
+
+    value = getattr(self._params, method)(key, *args, **kwargs)
+    self._cache[cache_key] = (now, value)
+    return value
+
+  def get(self, key: str, *args: Any, **kwargs: Any) -> Any:
+    return self._read("get", key, *args, **kwargs)
+
+  def get_bool(self, key: str, *args: Any, **kwargs: Any) -> bool:
+    return self._read("get_bool", key, *args, **kwargs)
+
+  def get_int(self, key: str, *args: Any, **kwargs: Any) -> int:
+    return self._read("get_int", key, *args, **kwargs)
+
+  def get_float(self, key: str, *args: Any, **kwargs: Any) -> float:
+    return self._read("get_float", key, *args, **kwargs)
+
+  def invalidate(self, key: str | None = None) -> None:
+    if key is None:
+      self._cache.clear()
+      return
+    self._cache = {cache_key: value for cache_key, value in self._cache.items()
+                   if cache_key[1] != key}
+
+  def put(self, key: str, value: Any, *args: Any, **kwargs: Any) -> None:
+    self._params.put(key, value, *args, **kwargs)
+    self.invalidate(key)
+
+  def put_bool(self, key: str, value: bool, *args: Any, **kwargs: Any) -> None:
+    self._params.put_bool(key, value, *args, **kwargs)
+    self.invalidate(key)
+
+  def put_int(self, key: str, value: int, *args: Any, **kwargs: Any) -> None:
+    self._params.put_int(key, value, *args, **kwargs)
+    self.invalidate(key)
+
+  def put_float(self, key: str, value: float, *args: Any, **kwargs: Any) -> None:
+    self._params.put_float(key, value, *args, **kwargs)
+    self.invalidate(key)
+
+  def put_nonblocking(self, key: str, value: Any) -> None:
+    self._params.put_nonblocking(key, value)
+    self.invalidate(key)
+
+  def put_bool_nonblocking(self, key: str, value: bool) -> None:
+    self._params.put_bool_nonblocking(key, value)
+    self.invalidate(key)
+
+  def remove(self, key: str) -> None:
+    self._params.remove(key)
+    self.invalidate(key)
+
+  def clear_all(self, *args: Any, **kwargs: Any) -> None:
+    self._params.clear_all(*args, **kwargs)
+    self.invalidate()
+
+  def __getattr__(self, name: str) -> Any:
+    return getattr(self._params, name)
+
+
+_SHARED_UI_PARAMS: UIParamCache | None = None
+
+
+def shared_ui_params() -> UIParamCache:
+  """Return the cache shared by BIG UI views and settings panels."""
+  global _SHARED_UI_PARAMS
+  if _SHARED_UI_PARAMS is None:
+    _SHARED_UI_PARAMS = UIParamCache()
+  return _SHARED_UI_PARAMS
diff --git a/selfdrive/ui/onroad/augmented_road_view.py b/selfdrive/ui/onroad/augmented_road_view.py
index 48102e402..36c475f8c 100644
--- a/selfdrive/ui/onroad/augmented_road_view.py
+++ b/selfdrive/ui/onroad/augmented_road_view.py
@@ -145,7 +145,7 @@ class AugmentedRoadView(CameraView):
     pass
 
   def _get_border_width(self) -> int:
-    return get_border_width(UI_BORDER_SIZE, ui_state.params)
+    return get_border_width(UI_BORDER_SIZE, ui_state.ui_params)
 
   def _draw_border(self, rect: rl.Rectangle):
     border_width = self._get_border_width()
@@ -179,7 +179,8 @@ class AugmentedRoadView(CameraView):
     return self._is_in_reverse()
 
   def _update_reverse_driver_camera_state(self) -> bool:
-    should_force_driver = ui_state.started and ui_state.params.get_bool("DriverCamera") and self._is_in_reverse()
+    params = ui_state.ui_params
+    should_force_driver = ui_state.started and params.get_bool("DriverCamera") and self._is_in_reverse()
     if not should_force_driver:
       self._reverse_driver_camera_frames = 0
       self._reverse_driver_camera_active = False
@@ -191,7 +192,8 @@ class AugmentedRoadView(CameraView):
 
   @staticmethod
   def _camera_view() -> int:
-    camera_view = ui_state.params.get_int("CameraView", return_default=True, default=CAMERA_VIEW_WIDE)
+    params = ui_state.ui_params
+    camera_view = params.get_int("CameraView", return_default=True, default=CAMERA_VIEW_WIDE)
     if camera_view not in (CAMERA_VIEW_AUTO, CAMERA_VIEW_DRIVER, CAMERA_VIEW_STANDARD, CAMERA_VIEW_WIDE, CAMERA_VIEW_NONE):
       return CAMERA_VIEW_WIDE
     return camera_view
diff --git a/selfdrive/ui/onroad/driver_camera_dialog.py b/selfdrive/ui/onroad/driver_camera_dialog.py
index e66e04b82..405df20d3 100644
--- a/selfdrive/ui/onroad/driver_camera_dialog.py
+++ b/selfdrive/ui/onroad/driver_camera_dialog.py
@@ -15,11 +15,13 @@ class DriverCameraDialog(CameraView):
     self.driver_state_renderer = DriverStateRenderer()
     # TODO: this can grow unbounded, should be given some thought
     device.add_interactive_timeout_callback(gui_app.pop_widget)
-    ui_state.params.put_bool("IsDriverViewEnabled", True)
+    gui_app.set_render_mode(True)
+    ui_state.ui_params.put_bool("IsDriverViewEnabled", True)
 
   def hide_event(self):
     super().hide_event()
-    ui_state.params.put_bool("IsDriverViewEnabled", False)
+    gui_app.set_render_mode(ui_state.started)
+    ui_state.ui_params.put_bool("IsDriverViewEnabled", False)
     self.close()
 
   def _handle_mouse_release(self, _):
diff --git a/selfdrive/ui/onroad/exp_button.py b/selfdrive/ui/onroad/exp_button.py
index d2476c2b3..3783b5341 100644
--- a/selfdrive/ui/onroad/exp_button.py
+++ b/selfdrive/ui/onroad/exp_button.py
@@ -1,6 +1,5 @@
 import time
 import pyray as rl
-from openpilot.common.params import Params
 from openpilot.selfdrive.ui.ui_state import ui_state
 from openpilot.system.ui.lib.application import gui_app
 from openpilot.system.ui.widgets import Widget
@@ -15,7 +14,7 @@ from openpilot.starpilot.common.experimental_state import (
 class ExpButton(Widget):
   def __init__(self, button_size: int, icon_size: int):
     super().__init__()
-    self._params = Params()
+    self._params = ui_state.ui_params
     self._experimental_mode: bool = False
     self._engageable: bool = False
 
diff --git a/selfdrive/ui/onroad/model_renderer.py b/selfdrive/ui/onroad/model_renderer.py
index 47d437ac7..b53f2cad5 100644
--- a/selfdrive/ui/onroad/model_renderer.py
+++ b/selfdrive/ui/onroad/model_renderer.py
@@ -4,7 +4,6 @@ import pyray as rl
 from cereal import messaging, car
 from dataclasses import dataclass, field
 from openpilot.common.filter_simple import FirstOrderFilter
-from openpilot.common.params import Params
 from openpilot.common.constants import CV
 from openpilot.selfdrive.locationd.calibrationd import HEIGHT_INIT
 from openpilot.selfdrive.ui.lib.starpilot_theme import get_param_color, get_theme_color, get_visual_color, is_stock_color_scheme, with_alpha
@@ -88,7 +87,7 @@ class ModelRenderer(Widget):
     self._rainbow_path = RainbowPath()
 
     # Get longitudinal control setting from car parameters
-    self._params = Params()
+    self._params = ui_state.ui_params
     if car_params := self._params.get("CarParams"):
       cp = messaging.log_from_bytes(car_params, car.CarParams)
       self._longitudinal_control = cp.openpilotLongitudinalControl
diff --git a/selfdrive/ui/onroad/starpilot/compass.py b/selfdrive/ui/onroad/starpilot/compass.py
index b52683825..96d8e9991 100644
--- a/selfdrive/ui/onroad/starpilot/compass.py
+++ b/selfdrive/ui/onroad/starpilot/compass.py
@@ -1,7 +1,8 @@
 from openpilot.selfdrive.ui.ui_state import ui_state
 
 def get_compass_text() -> str | None:
-  if not ui_state.params.get_bool("Compass"):
+  params = ui_state.ui_params
+  if not params.get_bool("Compass"):
     return None
 
   # Retrieve bearing
diff --git a/selfdrive/ui/onroad/starpilot/developer_sidebar.py b/selfdrive/ui/onroad/starpilot/developer_sidebar.py
index 724dfce00..d870c1970 100644
--- a/selfdrive/ui/onroad/starpilot/developer_sidebar.py
+++ b/selfdrive/ui/onroad/starpilot/developer_sidebar.py
@@ -3,7 +3,6 @@ import time
 import re
 import json
 from cereal import car
-from openpilot.common.params import Params
 from openpilot.selfdrive.ui.ui_state import ui_state
 from openpilot.system.ui.lib.application import gui_app, FontWeight, FONT_SCALE
 from openpilot.system.ui.lib.text_measure import measure_text_cached
@@ -64,7 +63,7 @@ def _setting_changed(value: float, reference: float) -> bool:
 
 class DeveloperSidebar:
   def __init__(self):
-    self._params = Params()
+    self._params = ui_state.ui_params
     self._font_bold = gui_app.font(FontWeight.SEMI_BOLD)
     self._last_toggles_check = 0.0
     self._cached_metrics = [0] * 7
diff --git a/selfdrive/ui/onroad/starpilot/navigation_card.py b/selfdrive/ui/onroad/starpilot/navigation_card.py
index b856126b5..23be70e1c 100644
--- a/selfdrive/ui/onroad/starpilot/navigation_card.py
+++ b/selfdrive/ui/onroad/starpilot/navigation_card.py
@@ -100,8 +100,9 @@ class NavigationCardRenderer(Widget):
       self._collapsed = new_state
 
   def _cancel_navigation(self) -> None:
+    params = ui_state.ui_params
     try:
-      ui_state.params.remove("NavDestination")
+      params.remove("NavDestination")
     except Exception:
       pass
 
@@ -162,14 +163,15 @@ class NavigationCardRenderer(Widget):
     return self._icons[icon_name]
 
   def _update_state(self) -> None:
-    self._enabled = ui_state.params.get_bool("NavigationUI")
+    params = ui_state.ui_params
+    self._enabled = params.get_bool("NavigationUI")
     self._valid = False
     self._interactive_rect = rl.Rectangle(0, 0, 0, 0)
 
     if not self._enabled:
       return
 
-    if not (ui_state.params.get("NavDestination") or ""):
+    if not (params.get("NavDestination") or ""):
       return
 
     raw_state = ui_state.params_memory.get("NavInstructionState") or {}
diff --git a/selfdrive/ui/onroad/starpilot/pedal_icons.py b/selfdrive/ui/onroad/starpilot/pedal_icons.py
index dae7d9ebc..0a4417a74 100644
--- a/selfdrive/ui/onroad/starpilot/pedal_icons.py
+++ b/selfdrive/ui/onroad/starpilot/pedal_icons.py
@@ -6,7 +6,7 @@ _RADIUS = 36
 _FONT_SIZE = 36
 
 def render_pedal_icons(start_x: float, start_y: float, font):
-  params = ui_state.params
+  params = ui_state.ui_params
   if not params.get_bool("PedalsOnUI"):
     return
 
diff --git a/selfdrive/ui/onroad/starpilot/slc_speed_limit.py b/selfdrive/ui/onroad/starpilot/slc_speed_limit.py
index cf363f15a..958c041b0 100644
--- a/selfdrive/ui/onroad/starpilot/slc_speed_limit.py
+++ b/selfdrive/ui/onroad/starpilot/slc_speed_limit.py
@@ -123,8 +123,9 @@ def _get_slc_state():
   plan = sm["starpilotPlan"]
   speed_limit_changed = plan.speedLimitChanged
 
-  show_slc = ui_state.params.get_bool("ShowSpeedLimits") or ui_state.params.get_bool("SpeedLimitController")
-  hide_sl = ui_state.params.get_bool("HideSpeedLimit")
+  params = ui_state.ui_params
+  show_slc = params.get_bool("ShowSpeedLimits") or params.get_bool("SpeedLimitController")
+  hide_sl = params.get_bool("HideSpeedLimit")
   unconfirmed_valid = plan.unconfirmedSlcSpeedLimit > 1
   # A pending (unconfirmed) limit overrides HideSpeedLimit so the prompt always shows.
   hide = not (speed_limit_changed and unconfirmed_valid) and hide_sl
@@ -134,10 +135,10 @@ def _get_slc_state():
     return None
 
   speed_conversion = CV.MS_TO_KPH if ui_state.is_metric else CV.MS_TO_MPH
-  show_offset = ui_state.params.get_bool("ShowSLCOffset")
+  show_offset = params.get_bool("ShowSLCOffset")
 
   dashboard_sl = sm["starpilotCarState"].dashboardSpeedLimit if sm.valid.get("starpilotCarState", False) else 0.0
-  vision_sl = ui_state.params_memory.get_float("VisionSpeedLimit") if ui_state.params.get_bool("VisionSpeedLimitDetection") else 0.0
+  vision_sl = ui_state.params_memory.get_float("VisionSpeedLimit") if params.get_bool("VisionSpeedLimitDetection") else 0.0
 
   slc_overridden_speed = plan.slcOverriddenSpeed
   # Driver override takes precedence over the planner's limit when active.
@@ -171,7 +172,7 @@ def _get_slc_state():
     'speed_limit_changed': speed_limit_changed,
     'hide': hide,
     'show_offset': show_offset,
-    'use_vienna': ui_state.params.get_bool("UseVienna"),
+    'use_vienna': params.get_bool("UseVienna"),
     'offset_str': offset_str,
     'speed_conversion': speed_conversion,
     'speed_unit': " km/h" if ui_state.is_metric else " mph",
@@ -498,4 +499,3 @@ def render_speed_limit_at(state: dict, rect: rl.Rectangle, expanded: bool = Fals
     _draw_sources_bubble(state, pill_rect, visual_rect)
 
   return pill_rect
-
diff --git a/selfdrive/ui/onroad/starpilot/starpilot_border.py b/selfdrive/ui/onroad/starpilot/starpilot_border.py
index 32de7e5d4..b2a6f4dee 100644
--- a/selfdrive/ui/onroad/starpilot/starpilot_border.py
+++ b/selfdrive/ui/onroad/starpilot/starpilot_border.py
@@ -56,7 +56,8 @@ def _csc_state():
     return None
 
   plan = sm["starpilotPlan"]
-  if plan.speedLimitChanged or not ui_state.params.get_bool("ShowCSCStatus"):
+  params = ui_state.ui_params
+  if plan.speedLimitChanged or not params.get_bool("ShowCSCStatus"):
     return None
 
   car_state = sm["carState"]
@@ -176,8 +177,9 @@ def render_background_effects(rect: rl.Rectangle, border_width: float):
   # 1. Turn Signal and Blind Spot indicators
   car_state = sm["carState"] if sm.valid.get("carState", False) else None
   if car_state:
-    show_signal = ui_state.params.get_bool("SignalMetrics")
-    show_blindspot = ui_state.params.get_bool("BlindSpotMetrics")
+    params = ui_state.ui_params
+    show_signal = params.get_bool("SignalMetrics")
+    show_blindspot = params.get_bool("BlindSpotMetrics")
     if show_signal or show_blindspot:
       left_blindspot = car_state.leftBlindspot
       right_blindspot = car_state.rightBlindspot
@@ -221,7 +223,7 @@ def render_background_effects(rect: rl.Rectangle, border_width: float):
   # 2. Steering Torque Border
   car_control = sm["carControl"] if sm.valid.get("carControl", False) else None
   if car_control:
-    show_steering = ui_state.params.get_bool("ShowSteering")
+    show_steering = ui_state.ui_params.get_bool("ShowSteering")
     if show_steering:
       torque = -car_control.actuators.torque
       abs_torque = abs(torque)
diff --git a/selfdrive/ui/onroad/starpilot/starpilot_onroad_view.py b/selfdrive/ui/onroad/starpilot/starpilot_onroad_view.py
index 58fbc0e2c..2392a913a 100644
--- a/selfdrive/ui/onroad/starpilot/starpilot_onroad_view.py
+++ b/selfdrive/ui/onroad/starpilot/starpilot_onroad_view.py
@@ -1,7 +1,6 @@
 import pyray as rl
 import time
 from msgq.visionipc import VisionStreamType
-from openpilot.common.params import Params
 from openpilot.selfdrive.ui.onroad.augmented_road_view import AugmentedRoadView
 from openpilot.selfdrive.ui.onroad.starpilot.starpilot_border import render_behind, render_overlay, render_background_effects
 from openpilot.selfdrive.ui.onroad.starpilot.path import render_adjacent_lanes, render_path_edges
@@ -31,7 +30,7 @@ AlertSize = log.SelfdriveState.AlertSize
 class StarPilotOnroadView(AugmentedRoadView):
   def __init__(self, stream_type: VisionStreamType = VisionStreamType.VISION_STREAM_ROAD):
     super().__init__(stream_type)
-    self._params = Params()
+    self._params = ui_state.ui_params
 
     self._font_bold = gui_app.font(FontWeight.BOLD)
     self._font_medium = gui_app.font(FontWeight.MEDIUM)
diff --git a/selfdrive/ui/onroad/starpilot/stopping_point.py b/selfdrive/ui/onroad/starpilot/stopping_point.py
index eb823f01c..4eb067bc6 100644
--- a/selfdrive/ui/onroad/starpilot/stopping_point.py
+++ b/selfdrive/ui/onroad/starpilot/stopping_point.py
@@ -14,7 +14,7 @@ def _draw_poly_outline(cx: float, cy: float, sides: int, radius: float, rotation
     rl.draw_line_ex(p1, p2, thickness, color)
 
 def render_stopping_point(renderer, font):
-  params = ui_state.params
+  params = ui_state.ui_params
   if not params.get_bool("ShowStoppingPoint"):
     return
 
diff --git a/selfdrive/ui/onroad/starpilot/widgets/pedal_icons.py b/selfdrive/ui/onroad/starpilot/widgets/pedal_icons.py
index 94a6ef06e..bb5967907 100644
--- a/selfdrive/ui/onroad/starpilot/widgets/pedal_icons.py
+++ b/selfdrive/ui/onroad/starpilot/widgets/pedal_icons.py
@@ -12,7 +12,7 @@ class PedalIconsWidget(LayoutWidget):
 
   @property
   def is_visible(self) -> bool:
-    params = ui_state.params
+    params = ui_state.ui_params
     if not params.get_bool("PedalsOnUI"):
       return False
     # Only render when car state is valid
diff --git a/selfdrive/ui/onroad/starpilot/widgets/personality_button.py b/selfdrive/ui/onroad/starpilot/widgets/personality_button.py
index 05b809536..df7eea759 100644
--- a/selfdrive/ui/onroad/starpilot/widgets/personality_button.py
+++ b/selfdrive/ui/onroad/starpilot/widgets/personality_button.py
@@ -12,7 +12,8 @@ class PersonalityButtonWidget(LayoutWidget):
 
   @property
   def is_visible(self) -> bool:
-    toggle_on = ui_state.params.get_bool("OnroadDistanceButton")
+    params = ui_state.ui_params
+    toggle_on = params.get_bool("OnroadDistanceButton")
     return bool(toggle_on and ui_state.started and ui_state.has_longitudinal_control)
 
   def get_size(self) -> tuple[float, float]:
diff --git a/selfdrive/ui/onroad/starpilot/widgets/speed_limit.py b/selfdrive/ui/onroad/starpilot/widgets/speed_limit.py
index da3909a9c..63e28d2b5 100644
--- a/selfdrive/ui/onroad/starpilot/widgets/speed_limit.py
+++ b/selfdrive/ui/onroad/starpilot/widgets/speed_limit.py
@@ -47,7 +47,8 @@ class SpeedLimitWidget(LayoutWidget):
   def _render(self, rect: rl.Rectangle) -> None:
     if self._slc_state is None:
       return
-    expanded = ui_state.params.get_bool("SpeedLimitSources")
+    params = ui_state.ui_params
+    expanded = params.get_bool("SpeedLimitSources")
     self._pill_rect = render_speed_limit_at(self._slc_state, rect, expanded)
 
   def _handle_mouse_press(self, mouse_pos) -> None:
@@ -59,8 +60,9 @@ class SpeedLimitWidget(LayoutWidget):
         self._pill_rect.height + 40
       )
       if rl.check_collision_point_rec(mouse_pos, hit_rect):
-        current = ui_state.params.get_bool("SpeedLimitSources")
-        Params().put_bool("SpeedLimitSources", not current)
+        params = ui_state.ui_params
+        current = params.get_bool("SpeedLimitSources")
+        params.put_bool("SpeedLimitSources", not current)
         return
 
     state = _get_slc_state()
diff --git a/selfdrive/ui/tests/test_aethergrid.py b/selfdrive/ui/tests/test_aethergrid.py
index b79337e62..2ffd1898b 100644
--- a/selfdrive/ui/tests/test_aethergrid.py
+++ b/selfdrive/ui/tests/test_aethergrid.py
@@ -2,7 +2,7 @@ import importlib
 import sys
 import types
 import unittest
-from unittest.mock import MagicMock
+from unittest.mock import MagicMock, patch
 
 
 MODULE_NAME = "openpilot.selfdrive.ui.layouts.settings.starpilot.aethergrid"
@@ -32,6 +32,7 @@ def _install_aethergrid_stubs():
     Texture2D=type("Texture2D", (), {}),
     Font=type("Font", (), {}),
     GuiTextAlignment=types.SimpleNamespace(TEXT_ALIGN_CENTER=0),
+    BlendMode=types.SimpleNamespace(BLEND_ALPHA_PREMULTIPLY=1),
     WHITE=types.SimpleNamespace(r=255, g=255, b=255, a=255),
     draw_rectangle_rounded=lambda *a, **k: None,
     draw_rectangle_rounded_lines_ex=lambda *a, **k: None,
@@ -44,6 +45,8 @@ def _install_aethergrid_stubs():
     draw_line_ex=lambda *a, **k: None,
     draw_triangle=lambda *a, **k: None,
     draw_texture_pro=lambda *a, **k: None,
+    begin_blend_mode=lambda *a, **k: None,
+    end_blend_mode=lambda *a, **k: None,
     draw_text_ex=lambda *a, **k: None,
     check_collision_point_rec=lambda p, r: (r.x <= p.x <= r.x + r.width) and (r.y <= p.y <= r.y + r.height),
     get_frame_time=lambda: 0.016,
@@ -153,10 +156,13 @@ def _install_panel_stubs(aethergrid):
   sectioned_mod = types.ModuleType(SECTIONED_PANEL_MODULE_NAME)
   sectioned_mod.SectionedTileLayout = type("SectionedTileLayout", (), {})
   sectioned_mod.TileSection = type("TileSection", (), {})
+  starpilot_variables_mod = types.ModuleType("openpilot.starpilot.common.starpilot_variables")
+  starpilot_variables_mod.update_starpilot_toggles = lambda: None
 
   _register_modules({
     SECTIONED_PANEL_MODULE_NAME: sectioned_mod,
     "openpilot.common.params": types.SimpleNamespace(Params=type("Params", (), {}), UnknownKeyName=Exception),
+    "openpilot.starpilot.common.starpilot_variables": starpilot_variables_mod,
     MODULE_NAME: aethergrid,
   })
 
@@ -251,6 +257,58 @@ class TestAethergridContracts(unittest.TestCase):
 
     self.assertEqual(tile.get_status(), "Download 50%")
 
+  def test_custom_icon_draws_directly_while_cache_fill_is_pending(self):
+    mod = _import_aethergrid()
+    scribble = sys.modules["openpilot.selfdrive.ui.layouts.settings.starpilot.scribble"]
+    geometry = MagicMock()
+    cache = MagicMock(return_value=None)
+
+    color = mod.rl.Color(255, 255, 255, 255)
+    with patch.object(scribble, "_draw_custom_icon_geometry", geometry), \
+         patch.object(scribble.gui_app, "cached_render_texture", cache, create=True):
+      scribble.draw_custom_icon("sound", 10, 20, 1.0, color)
+
+    cache.assert_called_once()
+    geometry.assert_called_once_with("sound", 10, 20, 1.0, color)
+
+  def test_custom_icon_uses_completed_cache_without_redrawing_geometry(self):
+    mod = _import_aethergrid()
+    scribble = sys.modules["openpilot.selfdrive.ui.layouts.settings.starpilot.scribble"]
+    geometry = MagicMock()
+    cache = MagicMock(return_value=object())
+    draw_texture = MagicMock()
+
+    with patch.object(scribble, "_draw_custom_icon_geometry", geometry), \
+         patch.object(scribble.gui_app, "cached_render_texture", cache, create=True), \
+         patch.object(scribble.rl, "draw_texture_pro", draw_texture):
+      scribble.draw_custom_icon("sound", 10, 20, 1.0, mod.rl.Color(255, 255, 255, 255))
+
+    geometry.assert_not_called()
+    draw_texture.assert_called_once()
+    destination = draw_texture.call_args.args[2]
+    self.assertLess(destination.x, 10)
+    self.assertLess(destination.y, 20)
+
+  def test_translucent_custom_icon_uses_premultiplied_blending(self):
+    mod = _import_aethergrid()
+    scribble = sys.modules["openpilot.selfdrive.ui.layouts.settings.starpilot.scribble"]
+    geometry = MagicMock()
+    cache = MagicMock(return_value=object())
+    begin_blend = MagicMock()
+    end_blend = MagicMock()
+
+    color = mod.rl.Color(160, 170, 185, 80)
+    with patch.object(scribble, "_draw_custom_icon_geometry", geometry), \
+         patch.object(scribble.gui_app, "cached_render_texture", cache, create=True), \
+         patch.object(scribble.rl, "begin_blend_mode", begin_blend), \
+         patch.object(scribble.rl, "end_blend_mode", end_blend):
+      scribble.draw_custom_icon("first_aid", 10, 20, 0.8, color)
+
+    cache.assert_called_once()
+    geometry.assert_not_called()
+    begin_blend.assert_called_once_with(mod.rl.BlendMode.BLEND_ALPHA_PREMULTIPLY)
+    end_blend.assert_called_once()
+
   def test_tile_grid_reflows_to_wider_tiles_when_width_is_tight(self):
     mod = _import_aethergrid()
     grid = mod.TileGrid(columns=None, padding=mod.SPACING.tile_gap)
diff --git a/selfdrive/ui/tests/test_ui_param_cache.py b/selfdrive/ui/tests/test_ui_param_cache.py
new file mode 100644
index 000000000..badda96ec
--- /dev/null
+++ b/selfdrive/ui/tests/test_ui_param_cache.py
@@ -0,0 +1,121 @@
+import unittest
+
+from openpilot.selfdrive.ui.lib.ui_param_cache import UIParamCache
+
+
+class FakeParams:
+  def __init__(self):
+    self.values = {"enabled": False, "count": 1}
+    self.calls = []
+
+  def get(self, key, **_kwargs):
+    self.calls.append(("get", key))
+    return self.values.get(key)
+
+  def get_bool(self, key, **_kwargs):
+    self.calls.append(("get_bool", key))
+    return bool(self.values.get(key, False))
+
+  def get_int(self, key, **_kwargs):
+    self.calls.append(("get_int", key))
+    return int(self.values.get(key, 0))
+
+  def get_float(self, key, **_kwargs):
+    self.calls.append(("get_float", key))
+    return float(self.values.get(key, 0.0))
+
+  def put(self, key, value, **_kwargs):
+    self.values[key] = value
+
+  def put_bool(self, key, value, **_kwargs):
+    self.values[key] = value
+
+  def put_int(self, key, value, **_kwargs):
+    self.values[key] = value
+
+  def put_float(self, key, value, **_kwargs):
+    self.values[key] = value
+
+  def put_nonblocking(self, key, value):
+    self.values[key] = value
+
+  def put_bool_nonblocking(self, key, value):
+    self.values[key] = value
+
+  def remove(self, key):
+    self.values.pop(key, None)
+
+  def clear_all(self, marker=None):
+    self.calls.append(("clear_all", marker))
+    self.values.clear()
+
+
+class TestUIParamCache(unittest.TestCase):
+  def test_reads_are_shared_until_ttl(self):
+    now = [0.0]
+    params = FakeParams()
+    cached = UIParamCache(params, ttl=0.1, clock=lambda: now[0])
+
+    self.assertFalse(cached.get_bool("enabled"))
+    self.assertFalse(cached.get_bool("enabled"))
+    self.assertEqual(params.calls, [("get_bool", "enabled")])
+
+    now[0] = 0.11
+    params.values["enabled"] = True
+    self.assertTrue(cached.get_bool("enabled"))
+    self.assertEqual(params.calls.count(("get_bool", "enabled")), 2)
+
+  def test_writes_invalidate_immediately(self):
+    params = FakeParams()
+    cached = UIParamCache(params, ttl=10.0)
+
+    self.assertFalse(cached.get_bool("enabled"))
+    cached.put_bool("enabled", True)
+    self.assertTrue(cached.get_bool("enabled"))
+    self.assertEqual(params.calls.count(("get_bool", "enabled")), 2)
+
+  def test_zero_ttl_disables_caching(self):
+    params = FakeParams()
+    cached = UIParamCache(params, ttl=0.0)
+
+    self.assertFalse(cached.get_bool("enabled"))
+    params.values["enabled"] = True
+    self.assertTrue(cached.get_bool("enabled"))
+    self.assertEqual(params.calls.count(("get_bool", "enabled")), 2)
+
+  def test_all_write_paths_invalidate(self):
+    operations = (
+      lambda cache: cache.put("enabled", True),
+      lambda cache: cache.put_bool("enabled", True),
+      lambda cache: cache.put_int("enabled", 1),
+      lambda cache: cache.put_float("enabled", 1.0),
+      lambda cache: cache.put_nonblocking("enabled", True),
+      lambda cache: cache.put_bool_nonblocking("enabled", True),
+    )
+    for operation in operations:
+      with self.subTest(operation=operation):
+        params = FakeParams()
+        cached = UIParamCache(params, ttl=10.0)
+        self.assertFalse(cached.get_bool("enabled"))
+        operation(cached)
+        self.assertTrue(cached.get_bool("enabled"))
+        self.assertEqual(params.calls.count(("get_bool", "enabled")), 2)
+
+  def test_remove_and_clear_all_invalidate(self):
+    params = FakeParams()
+    cached = UIParamCache(params, ttl=10.0)
+
+    self.assertTrue(cached.get_int("count"))
+    cached.remove("count")
+    self.assertEqual(cached.get_int("count"), 0)
+
+    self.assertFalse(cached.get_bool("enabled"))
+    params.values["enabled"] = True
+    cached.clear_all("flag")
+    params.values["enabled"] = True
+    self.assertTrue(cached.get_bool("enabled"))
+    self.assertIn(("clear_all", "flag"), params.calls)
+
+
+if __name__ == "__main__":
+  unittest.main()
diff --git a/selfdrive/ui/ui_state.py b/selfdrive/ui/ui_state.py
index 59393f5aa..74b170914 100644
--- a/selfdrive/ui/ui_state.py
+++ b/selfdrive/ui/ui_state.py
@@ -10,6 +10,7 @@ from openpilot.common.filter_simple import FirstOrderFilter
 from openpilot.common.params import Params
 from openpilot.common.swaglog import cloudlog
 from openpilot.selfdrive.ui.lib.prime_state import PrimeState
+from openpilot.selfdrive.ui.lib.ui_param_cache import shared_ui_params
 from openpilot.system.hardware.usb import chestnut_present
 from openpilot.system.ui.lib.application import gui_app
 from openpilot.system.hardware import HARDWARE, PC
@@ -35,6 +36,9 @@ class UIState:
 
   def _initialize(self):
     self.params = Params()
+    # BIG UI views use this read-through cache; keep ``params`` untouched for
+    # MICI and for non-rendering callers that rely on its exact semantics.
+    self.ui_params = shared_ui_params() if gui_app.big_ui() else self.params
     self.params_memory = Params(memory=True)
     self.sm = messaging.SubMaster(
       [
@@ -176,24 +180,26 @@ class UIState:
       self.light_sensor = -1
 
     # Trust hardwared's filtered started state; raw ignition can flap on Toyota.
-    force_onroad = self.params.get_bool("ForceOnroad")
-    force_offroad = self.params.get_bool("ForceOffroad")
+    # Use the BIG-UI cache here as this path runs once per render iteration.
+    params = self.ui_params
+    force_onroad = params.get_bool("ForceOnroad")
+    force_offroad = params.get_bool("ForceOffroad")
     started = self.sm["deviceState"].started
     started |= force_onroad
     started &= not force_offroad
     self.started = started
 
     # Update recording audio state
-    self.recording_audio = self.params.get_bool("RecordAudio") and self.started
+    self.recording_audio = params.get_bool("RecordAudio") and self.started
 
-    self.is_metric = self.params.get_bool("IsMetric")
-    self.always_on_dm = self.params.get_bool("AlwaysOnDM")
+    self.is_metric = params.get_bool("IsMetric")
+    self.always_on_dm = params.get_bool("AlwaysOnDM")
     now = time.monotonic()
     if now - self._usbgpu_update_time >= USBGPU_POLL_INTERVAL:
       self.usbgpu = chestnut_present()
       self._usbgpu_update_time = now
-    self.usbgpu_compiled = self.params.get_bool("UsbGpuCompiled")
-    self.usbgpu_active = self.params.get_bool("UsbGpuActive")
+    self.usbgpu_compiled = params.get_bool("UsbGpuCompiled")
+    self.usbgpu_active = params.get_bool("UsbGpuActive")
     self.switchback_mode_enabled = self.params_memory.get_bool("SwitchbackModeEnabled") if self.started else False
     if self.sm.valid.get("starpilotCarState", False):
       starpilot_car_state = self.sm["starpilotCarState"]
@@ -269,7 +275,7 @@ class Device:
     self._interactive_timeout_callbacks: list[Callable] = []
     self._prev_timed_out = False
     self._awake: bool = True
-    self._params = Params()
+    self._params = ui_state.ui_params
 
     self._offroad_brightness: int = BACKLIGHT_OFFROAD
     self._last_brightness: int = 0
diff --git a/selfdrive/ui/widgets/exp_mode_button.py b/selfdrive/ui/widgets/exp_mode_button.py
index b1fd40f14..2e578aea0 100644
--- a/selfdrive/ui/widgets/exp_mode_button.py
+++ b/selfdrive/ui/widgets/exp_mode_button.py
@@ -1,5 +1,4 @@
 import pyray as rl
-from openpilot.common.params import Params
 from openpilot.system.ui.lib.application import gui_app, FontWeight, FONT_SCALE
 from openpilot.system.ui.lib.multilang import tr
 from openpilot.system.ui.lib.text_measure import measure_text_cached
@@ -17,7 +16,7 @@ class ExperimentalModeButton(Widget):
     self.horizontal_padding = 25
     self.button_height = 125
 
-    self.params = Params()
+    self.params = ui_state.ui_params
     self.experimental_mode = requested_experimental_mode(self.params, ui_state.params_memory)
     self.mode_variant = get_mode_banner_variant(self.params, ui_state.params_memory)
 
diff --git a/system/ui/lib/application.py b/system/ui/lib/application.py
index 6fb8dd5f1..fd85dd25f 100644
--- a/system/ui/lib/application.py
+++ b/system/ui/lib/application.py
@@ -30,6 +30,8 @@ FPS_CRITICAL_THRESHOLD = 0.5  # Critical threshold for triggering strict actions
 MOUSE_THREAD_RATE = 140  # touch controller runs at 140Hz
 DESKTOP_MOUSE_THREAD_RATE = int(os.getenv("DESKTOP_MOUSE_RATE", "500"))
 DESKTOP_CLICK_DEBOUNCE = float(os.getenv("DESKTOP_CLICK_DEBOUNCE", "0.2"))
+UI_IDLE_FPS = int(os.getenv("UI_IDLE_FPS", "0"))
+UI_INTERACTION_FPS_DURATION = 1.25
 MAX_TOUCH_SLOTS = 2
 TOUCH_HISTORY_TIMEOUT = 3.0  # Seconds before touch points fade out
 
@@ -496,7 +498,14 @@ class GuiApplication:
     self._ffmpeg_stop_event: threading.Event | None = None
     self._progress_hook: Callable[[str], None] | None = None
     self._textures: dict[str, rl.Texture] = {}
+    self._cached_render_textures: dict[str, rl.RenderTexture] = {}
+    self._pending_render_textures: dict[str, tuple[int, int, Callable[[], None]]] = {}
     self._target_fps: int = _DEFAULT_FPS
+    self._full_target_fps: int = _DEFAULT_FPS
+    self._idle_target_fps: int = max(10, _DEFAULT_FPS // 4)
+    self._adaptive_rendering = False
+    self._full_rate_rendering = False
+    self._high_fps_until = 0.0
     self._last_fps_log_time: float = time.monotonic()
     self._burn_in_start_time = time.monotonic()
     self._frame = 0
@@ -538,6 +547,50 @@ class GuiApplication:
   def target_fps(self):
     return self._target_fps
 
+  def _set_target_fps(self, fps: int) -> None:
+    fps = max(1, int(fps))
+    if fps == self._target_fps:
+      return
+    rl.set_target_fps(0 if OFFSCREEN else fps)
+    self._target_fps = fps
+
+  def configure_adaptive_rendering(self, enabled: bool, idle_fps: int | None = None) -> None:
+    """Enable low-rate rendering for static BIG-UI offroad screens.
+
+    The normal target remains unchanged unless a caller opts in. This keeps
+    MICI and all existing non-BIG layouts on their current scheduling path.
+    """
+    # Recording feeds raw frames to ffmpeg at the fixed full FPS, so changing
+    # the producer rate would make idle portions play back too quickly.
+    self._adaptive_rendering = bool(enabled and not OFFSCREEN and not RECORD)
+    if idle_fps is None or idle_fps <= 0:
+      idle_fps = UI_IDLE_FPS if UI_IDLE_FPS > 0 else max(10, self._full_target_fps // 4)
+    self._idle_target_fps = min(self._full_target_fps, max(1, int(idle_fps)))
+    self._full_rate_rendering = False
+    self._high_fps_until = time.monotonic() + UI_INTERACTION_FPS_DURATION if self._adaptive_rendering else 0.0
+    if self._adaptive_rendering:
+      self._apply_render_mode()
+    else:
+      self._set_target_fps(self._full_target_fps)
+
+  def request_high_fps(self, duration: float = UI_INTERACTION_FPS_DURATION) -> None:
+    if not self._adaptive_rendering:
+      return
+    self._high_fps_until = max(self._high_fps_until, time.monotonic() + max(0.0, duration))
+    self._apply_render_mode()
+
+  def set_render_mode(self, active: bool) -> None:
+    if not self._adaptive_rendering:
+      return
+    self._full_rate_rendering = active
+    self._apply_render_mode()
+
+  def _apply_render_mode(self) -> None:
+    if not self._adaptive_rendering:
+      return
+    high_rate = self._full_rate_rendering or time.monotonic() < self._high_fps_until
+    self._set_target_fps(self._full_target_fps if high_rate else self._idle_target_fps)
+
   def request_close(self):
     self._window_close_requested = True
 
@@ -607,6 +660,7 @@ class GuiApplication:
       # OFFSCREEN disables FPS limiting for fast offline rendering (e.g. clips)
       rl.set_target_fps(0 if OFFSCREEN else fps)
 
+      self._full_target_fps = fps
       self._target_fps = fps
       self._set_styles()
       self._load_fonts()
@@ -681,6 +735,7 @@ class GuiApplication:
       prev_widget.set_enabled(False)
 
     self._nav_stack.append(widget)
+    self.request_high_fps()
     widget.show_event()
     widget.set_enabled(True)
 
@@ -702,6 +757,7 @@ class GuiApplication:
 
     widget = self._nav_stack.pop(idx_to_pop)
     widget.hide_event()
+    self.request_high_fps()
 
   def pop_widgets_to(self, widget: object, callback: Callable[[], None] | None = None, instant: bool = False):
     # Pops middle widgets instantly without animation then dismisses top, animated out if NavWidget
@@ -750,6 +806,8 @@ class GuiApplication:
 
   def set_should_render(self, should_render: bool):
     self._should_render = should_render
+    if should_render:
+      self.request_high_fps()
 
   def texture(self, asset_path: str, width: int | None = None, height: int | None = None,
               alpha_premultiply=False, keep_aspect_ratio=True, flip_x: bool = False) -> rl.Texture:
@@ -774,6 +832,62 @@ class GuiApplication:
     self._textures[cache_key] = texture_obj
     return texture_obj
 
+  def cached_render_texture(self, cache_key: str, width: int, height: int,
+                            render: Callable[[], None]) -> object | None:
+    """Return a cached texture, scheduling cache misses between frames.
+
+    Raylib render-texture modes are not nestable. Widgets call this while the
+    main framebuffer (often another render texture) is active, so cache misses
+    must be populated after the frame has been presented.
+    """
+    cached = self._cached_render_textures.get(cache_key)
+    if cached is not None:
+      return cached.texture
+
+    self._pending_render_textures.setdefault(
+      cache_key, (max(1, int(width)), max(1, int(height)), render)
+    )
+    return None
+
+  def _populate_render_texture_cache(self) -> None:
+    pending = self._pending_render_textures
+    self._pending_render_textures = {}
+    for cache_key, (width, height, render) in pending.items():
+      if cache_key in self._cached_render_textures:
+        continue
+
+      cached = rl.load_render_texture(max(1, int(width)), max(1, int(height)))
+      began_texture_mode = False
+      began_blend_mode = False
+      try:
+        rl.begin_texture_mode(cached)
+        began_texture_mode = True
+        rl.clear_background(rl.Color(0, 0, 0, 0))
+        # Preserve straight alpha while RGB is accumulated premultiplied. The
+        # resulting texture can then be composited with BLEND_ALPHA_PREMULTIPLY
+        # without squaring translucent vector alpha.
+        rl.rl_set_blend_factors_separate(
+          rl.RL_SRC_ALPHA, rl.RL_ONE_MINUS_SRC_ALPHA,
+          rl.RL_ONE, rl.RL_ONE_MINUS_SRC_ALPHA,
+          rl.RL_FUNC_ADD, rl.RL_FUNC_ADD,
+        )
+        rl.begin_blend_mode(rl.BlendMode.BLEND_CUSTOM_SEPARATE)
+        began_blend_mode = True
+        render()
+      except Exception:
+        if began_blend_mode:
+          rl.end_blend_mode()
+        if began_texture_mode:
+          rl.end_texture_mode()
+        rl.unload_render_texture(cached)
+        raise
+      else:
+        rl.end_blend_mode()
+        rl.end_texture_mode()
+      rl.set_texture_filter(cached.texture, rl.TextureFilter.TEXTURE_FILTER_BILINEAR)
+      rl.set_texture_wrap(cached.texture, rl.TextureWrap.TEXTURE_WRAP_CLAMP)
+      self._cached_render_textures[cache_key] = cached
+
   def _load_image_from_path(self, image_path: str, width: int | None = None, height: int | None = None,
                             alpha_premultiply: bool = False, keep_aspect_ratio: bool = True, flip_x: bool = False) -> rl.Image:
     """Load and resize an image, storing it for later automatic unloading."""
@@ -850,6 +964,11 @@ class GuiApplication:
       rl.unload_texture(texture)
     self._textures = {}
 
+    for render_texture in self._cached_render_textures.values():
+      rl.unload_render_texture(render_texture)
+    self._cached_render_textures = {}
+    self._pending_render_textures = {}
+
     for font in self._fonts.values():
       rl.unload_font(font)
     self._fonts = {}
@@ -890,6 +1009,7 @@ class GuiApplication:
 
       while not (self._window_close_requested or rl.window_should_close()):
         self._mark_progress("gui_app.loop_start")
+        self._apply_render_mode()
         if PC:
           # Thread is not used on PC, need to manually add mouse events.
           self._mouse._handle_mouse_event()
@@ -898,6 +1018,7 @@ class GuiApplication:
         self._mouse_events = self._mouse.get_events()
         if len(self._mouse_events) > 0:
           self._last_mouse_event = self._mouse_events[-1]
+          self.request_high_fps()
 
         # Skip rendering when screen is off
         if not self._should_render:
@@ -987,6 +1108,7 @@ class GuiApplication:
         self._mark_progress("gui_app.before_end_drawing")
         rl.end_drawing()
         self._mark_progress("gui_app.after_end_drawing")
+        self._populate_render_texture_cache()
 
         if RECORD:
           image = rl.load_image_from_texture(self._render_texture.texture)