diff --git a/common/params_keys.h b/common/params_keys.h
index f67779851..dcdc95e7d 100644
--- a/common/params_keys.h
+++ b/common/params_keys.h
@@ -62,8 +62,8 @@ inline static std::unordered_map<std::string, ParamKeyAttributes> keys = {
     {"GsmRoaming", {PERSISTENT, BOOL}},
     {"HardwareSerial", {PERSISTENT, STRING}},
     {"HasAcceptedTerms", {PERSISTENT, STRING, "0"}},
-    // Developer-only while each Bosch-A platform is being verified against real captures.
-    {"HondaBoschARadar", {PERSISTENT, BOOL, "0"}},
+    // Internal kill switch; the platform verification allowlist remains the hard safety gate.
+    {"HondaBoschARadar", {PERSISTENT, BOOL, "1"}},
     {"HondaGasFactorParams", {PERSISTENT, FLOAT}},
     {"HondaLateralPidKiScale", {PERSISTENT, FLOAT, "1.0", "1.0", 3}},
     {"HondaLateralPidKpScale", {PERSISTENT, FLOAT, "1.0", "1.0", 3}},
diff --git a/opendbc_repo/opendbc/car/honda/interface.py b/opendbc_repo/opendbc/car/honda/interface.py
index 03be29541..68c21bc50 100644
--- a/opendbc_repo/opendbc/car/honda/interface.py
+++ b/opendbc_repo/opendbc/car/honda/interface.py
@@ -48,7 +48,9 @@ class CarInterface(CarInterfaceBase):
       # HONDA_BOSCH_A describes the physical harness family. Radar remains unavailable until the
       # exact platform is added to HONDA_BOSCH_A_RADAR_VERIFIED after real-capture validation.
       try:
-        bosch_a_radar_tryout = not docs and Params().get_bool("HondaBoschARadar")
+        # The explicit default keeps the verified platform usable on installs that have not yet
+        # persisted the internal kill-switch parameter; the verified-platform set remains mandatory.
+        bosch_a_radar_tryout = not docs and Params().get_bool("HondaBoschARadar", default=True)
       except UnknownKeyName:
         bosch_a_radar_tryout = False
       ret.radarUnavailable = not (candidate in HONDA_BOSCH_A and
diff --git a/opendbc_repo/opendbc/car/honda/tests/test_bosch_a_radar.py b/opendbc_repo/opendbc/car/honda/tests/test_bosch_a_radar.py
index dc2c1b828..07de1243e 100644
--- a/opendbc_repo/opendbc/car/honda/tests/test_bosch_a_radar.py
+++ b/opendbc_repo/opendbc/car/honda/tests/test_bosch_a_radar.py
@@ -1164,10 +1164,11 @@ def test_bosch_a_toggle_can_close_verified_platform(monkeypatch):
     Params().put_bool("HondaBoschARadar", original)
 
 
-def test_bosch_a_toggle_defaults_off():
+def test_bosch_a_toggle_defaults_on_but_allowlist_still_gates_platforms():
   original = Params().get_bool("HondaBoschARadar")
   try:
     Params().remove("HondaBoschARadar")
-    assert Params().get_bool("HondaBoschARadar") is False
+    assert CarInterface.get_non_essential_params(CAR.HONDA_CIVIC_BOSCH).radarUnavailable is False
+    assert CarInterface.get_non_essential_params(CAR.HONDA_ACCORD).radarUnavailable is True
   finally:
     Params().put_bool("HondaBoschARadar", original)