diff --git a/openpilot/starpilot/flm/live_tracking_probe_process.py b/openpilot/starpilot/flm/live_tracking_probe_process.py
index 0a8a448e8e..a6b776fe85 100644
--- a/openpilot/starpilot/flm/live_tracking_probe_process.py
+++ b/openpilot/starpilot/flm/live_tracking_probe_process.py
@@ -37,14 +37,11 @@ def _literal_control(row):
   if type(row) is not ControlEvidence:
     raise ValueError('exact original control receipt required')
   _trace_key(row.effect_trace)
-  result = {}
-  for field in fields(ControlEvidence):
-    value = getattr(row, field.name)
-    if field.name == 'effect_trace':
-      result[field.name] = _literal_trace(value)
-    else:
-      _validate_primitive(value)
-      result[field.name] = value
+  result = {field.name: _literal_trace(row.effect_trace) if field.name == 'effect_trace' else getattr(row, field.name)
+            for field in fields(ControlEvidence)}
+  # Close every field together before any packing or source comparison. This
+  # avoids a separate native stack-budget walk for each scalar in every tick.
+  _validate_primitive(result)
   return result
 
 
diff --git a/openpilot/starpilot/flm/tests/test_literal_control.py b/openpilot/starpilot/flm/tests/test_literal_control.py
new file mode 100644
index 0000000000..452d3092f2
--- /dev/null
+++ b/openpilot/starpilot/flm/tests/test_literal_control.py
@@ -0,0 +1,59 @@
+from dataclasses import fields
+import pytest
+from openpilot.starpilot.flm.fullrate_collector import ControlEvidence
+from openpilot.starpilot.flm.live_tracking_probe_process import _literal_control
+
+
+def control():
+  # Literal transport only; this grants no live/native/controller authority.
+  return ControlEvidence(identity='transport-only',generation=1,control_ns=100,state_ns=99,
+    domain='normalized_torque',stage_revision='transport-only',response_revision='transport-only',
+    requested=-0.,features=(0.,),baseline_prediction=0.,enabled=False,manual=False,active=False,
+    valid=False,override=False,fault=False,saturated=False,limited=False,model_wobble=False,controller_chatter=False,
+    replay_inputs=(('complete',{'value':[1.,True,1]}),),live_applied_coordinates=(0.,)*30,
+    vehicle_model_anchor=(1.,2.,3.))
+
+
+def test_complete_literal_preserves_every_actual_field():
+  row=control()
+  literal=_literal_control(row)
+  assert list(literal)==[f.name for f in fields(ControlEvidence)]
+  assert all(literal[f.name]==getattr(row,f.name) for f in fields(ControlEvidence))
+
+
+@pytest.mark.parametrize('field',['requested','features','replay_snapshot','replay_inputs','stage_values','vehicle_model_anchor','live_applied_coordinates'])
+def test_unknown_leaf_never_executes_conversion_or_reducer(field):
+  calls=[]
+  class Trap:
+    def __reduce__(self):
+      calls.append('reduce')
+      raise AssertionError('foreign reducer')
+    def __float__(self):
+      calls.append('float')
+      raise AssertionError('foreign conversion')
+    def __iter__(self):
+      calls.append('iter')
+      raise AssertionError('foreign iteration')
+  row=control()
+  object.__setattr__(row,field,Trap())
+  with pytest.raises(ValueError):
+    _literal_control(row)
+  assert calls==[]
+
+
+@pytest.mark.parametrize('value',[float('nan'),float('inf'),1<<513,'x'*131073,tuple(range(8193))])
+def test_original_closed_graph_limits_still_refuse(value):
+  row=control()
+  object.__setattr__(row,'replay_inputs',(('invalid',value),))
+  with pytest.raises(ValueError):
+    _literal_control(row)
+
+
+def test_nested_mutation_is_rechecked_on_next_transport():
+  row=control()
+  nested: list[object]=[1.,True,1]
+  object.__setattr__(row,'replay_inputs',(('complete',nested),))
+  _literal_control(row)
+  nested.append(object())
+  with pytest.raises(ValueError):
+    _literal_control(row)
diff --git a/prebuilt.json b/prebuilt.json
index 35bf87526f..36759a10b3 100644
--- a/prebuilt.json
+++ b/prebuilt.json
@@ -1 +1 @@
-{"protected_inventory_sha256": "fcc7950cbccb4bf1ecb6dff3ad4d15f48041f0a9acc5b135d78736b07827a98e", "schema_version": 1}
+{"protected_inventory_sha256": "a873272c09f2fb77109a5a428ce301afb4ba353f7160d38cbc31bc9c84a269e2", "schema_version": 1}