> The userspace OS needs to be where control of any radio (bluetooth, wi-fi, cellular, nfc, uwb etc.) components happens, otherwise it would be difficult to be compliant in terms of regulatory requirements like a working Flight Mode.

The entities that are putting in backdoors don't respect the law, and obviously will do what they can to obfuscate the backdoor enough to pass regulatory reviews.

My threat model is precisely entities that don't respect law or are unethical. So, the question then boils down to whether current regulatory review processes can catch such backdoors and the people running these processes cannot be bribed or otherwise forced to skip proper review?