diff --git a/docs/kiss_modem_protocol.md b/docs/kiss_modem_protocol.md
index af82cc938..b91b619f9 100644
--- a/docs/kiss_modem_protocol.md
+++ b/docs/kiss_modem_protocol.md
@@ -45,6 +45,9 @@ commands normally. A detected USB disconnect/reset also ends the session.
 UART-to-USB adapters without a disconnect signal may require RETURN.
 If the radio2 settings change mid-session, USB stays quarantined until RETURN
 or disconnect, so leftover binary bytes cannot become CLI commands.
+For Espressif USB-Serial/JTAG (`303A:1001`), open the host port with DTR and
+RTS deasserted; those lines control boot/reset selection. Other USB CDC
+devices, including nRF52/TinyUSB, retain their normal DTR handling.
 
 ESP32 also supports `set kiss.transport tcp`. Enable station WiFi separately
 and connect to its address on TCP **5004**. The service accepts one client,
diff --git a/tools/hil/profile_switch.py b/tools/hil/profile_switch.py
index 4b66a6912..240f4db78 100644
--- a/tools/hil/profile_switch.py
+++ b/tools/hil/profile_switch.py
@@ -16,11 +16,13 @@ _run_sequences = itertools.count(secrets.randbelow(0x3fffffff) + 1)
 
 
 def configure_session(port):
-    # Native Espressif/Seeed/Adafruit USB and CP2102/CH340 bridges differ in DTR semantics.
-    # DTR keeps the native session active; on a bridge it can drive BOOT/GPIO0.
+    # ESP32-C3/S3 USB Serial/JTAG (303A:1001) maps asserted DTR to IO0.
+    # Leave it released across a firmware reboot. TinyUSB/nRF52 CDC still
+    # needs DTR; UART bridges can also drive BOOT/GPIO0 and keep it released.
     port.rts = False
     device = os.path.realpath(str(port.port)).casefold()
     port.dtr = any(info.vid in (0x303A, 0x2886, 0x239A)
+                   and (info.vid, getattr(info, "pid", None)) != (0x303A, 0x1001)
                    and os.path.realpath(str(info.device)).casefold() == device
                    for info in list_ports.comports())
 
diff --git a/tools/hil/test_profile_switch_host.py b/tools/hil/test_profile_switch_host.py
index 3451769c0..68138b6e9 100644
--- a/tools/hil/test_profile_switch_host.py
+++ b/tools/hil/test_profile_switch_host.py
@@ -98,14 +98,15 @@ class ResultReaderTests(unittest.TestCase):
         master, slave = os.openpty()
         try:
             device = os.ttyname(slave)
-            for vid, expected in ((0x10C4, False), (0x1A86, False),
-                                  (0x303A, True), (0x2886, True), (0x239A, True)):
-                with self.subTest(vid=vid):
+            for vid, pid, expected in ((0x10C4, 0xEA60, False), (0x1A86, 0x7523, False),
+                                       (0x303A, 0x1001, False), (0x303A, 0x4001, True),
+                                       (0x2886, 0x8045, True), (0x239A, 0x8029, True)):
+                with self.subTest(vid=vid, pid=pid):
                     port = PosixModemSerial()
                     port.port = device
                     try:
                         with patch("profile_switch.list_ports.comports", return_value=[
-                                SimpleNamespace(device=device, vid=vid)]):
+                                SimpleNamespace(device=device, vid=vid, pid=pid)]):
                             open_session(port)
                         self.assertFalse(port.has_reset_transition(), port.modem_edges)
                         self.assertEqual(port.modem_lines, {"dtr": expected, "rts": False})
@@ -170,11 +171,12 @@ class ResultReaderTests(unittest.TestCase):
         self.assertTrue(result["transport_recovered"])
 
     def test_native_usb_and_bridge_have_distinct_control_lines(self):
-        for vid, expected in ((0x303A, True), (0x2886, True), (0x239A, True),
-                              (0x1A86, False), (0x10C4, False), (None, False)):
+        for vid, pid, expected in ((0x303A, 0x1001, False), (0x303A, 0x4001, True),
+                                   (0x2886, 0x8045, True), (0x239A, 0x8029, True),
+                                   (0x1A86, 0x7523, False), (0x10C4, 0xEA60, False), (None, None, False)):
             port = SessionPort("test")
             with patch("profile_switch.list_ports.comports", return_value=[
-                    SimpleNamespace(device="TEST", vid=vid),
+                    SimpleNamespace(device="TEST", vid=vid, pid=pid),
                     SimpleNamespace(device="different", vid=0x303A)]):
                 configure_session(port)
             self.assertFalse(port.is_open)
@@ -196,9 +198,9 @@ class ResultReaderTests(unittest.TestCase):
             bridge_id = by_id / "usb-Silicon_Labs_CP2102-if00-port0"
             native_id.symlink_to(native)
             bridge_id.symlink_to(bridge)
-            inventory = [SimpleNamespace(device=str(native), vid=0x303A),
+            inventory = [SimpleNamespace(device=str(native), vid=0x303A, pid=0x1001),
                          SimpleNamespace(device=str(bridge), vid=0x10C4)]
-            for device, expected in ((native_id, True), (bridge_id, False)):
+            for device, expected in ((native_id, False), (bridge_id, False)):
                 with self.subTest(device=device.name):
                     port = SessionPort(str(device))
                     with patch("profile_switch.list_ports.comports", return_value=inventory):