It’s mostly a nothing burger. You basically need to have code already running on the chips. It’s less of a backdoor and more of just an undocumented function. That may sound scary but it’s rather common in production chips. In some ways it’s a good thing, it means there are now more possibilities for messing with the chip and doing fun stuff with it.

Nextnav

https://docs.fcc.gov/public/attachments/DA-24-776A1.txt

There’s already a startup trying to get the FCC to give them half of the 915mhz band (meshtastic, smart home stuff, ELRS, ham radio) for a pay to win GPS alternative.