I have a suspicion (based on absolutely no evidence, other than that I'm an Engineer, and expect Apple has some brain cells); that the way this feature works is

I have a suspicion (based on absolutely no evidence, other than that I'm an Engineer, and expect Apple has some brain cells); that the way this feature works is with a magnet and reed switch to physically disconnect the lines with no "communication" via software/firmware or other electronic means; Based on their "hardware only" wording for the newer devices, I'm inclined to believe this is the case.