Thank you for this. Your blink-register sketch is particularly helpful.
I realize you are primarily working on Arduino framework related issues, but do you have any insight on the behavior I’m seeing booting the stock ESP AT firmware (GitHub - espressif/esp-at: AT application for ESP32/ESP32-C2/ESP32-C3/ESP32-C6/ESP8266)?
To my surprise it appears like the external antenna is enabled by default: RSSI Reception is dramatically better simply connecting the external antenna after a stock boot. Or could this just be that its still using internal antenna but RF leakage and mere presence of external antenna is “boosting” the internal antenna?
I’ve tried fiddling bits of Pin 3 & Pin 14 and I can’t see any real effect (but perhaps I’m just doing it wrong!). The only real noticeable effect I see is whether or not the external antenna is connected to UFL port…