Set a reboot timer. It’ll shut down and dump the keys out of RAM putting it in the more difficult BFU state. That way if you phone is taken and not unlocked successfully by you within a day or so it’ll render itself much harder to crack.
Harsh truth, the entire bandwidth of all the HF bands combined, not just the ham allocations, fully DC to ~30MHz, is smaller than a single mediocre home internet connection (per Shannon Hartley theorem). If even 0.1% of the world started using ham radios to do so much as send the bare minimum of ultra compact text messages to each other the entire spectrum would be clogged to the point of uselessness.
HF is great for very localized communications disruptions, but a nationwide or worldwide internet failure would not remotely be helped via HF.
I’d argue the year of the Linux desktop passed years ago and now it’s just a saturation game. Most serious SW development is now on Linux laptops/desktops, Android owns the mobile space and versions are starting to make huge inroads in the laptop space. You can buy gaming systems running it trivially now.
Conversely, casual users of windows are dying off, fewer non technical people are using desktops for anything at all. Only institutional users are buying Windows keys and they’re some of the easiest to get on Linux because of the cost savings, particularly if you run Linux server infrastructure, a fight we already won over a decade ago.
I’m not intimately familiar with the BCM2711 but I believe it’s a reasonable, albeit somewhat overpowered, processor for the application. It can be put into a variety of low power states and probably pulled out of sleep by various events like the GSM chip sending packets or accelerometer motion (frequently the peripheral chips have dedicated “wakeup” pins that you can wire to interrupts). It’s not the most cost effective option by far, there are sub $5 microcontrollers with multiple cores for handling communications and real time motor control concurrently but you’d need to hire someone like me for a few months @$200/hr to write the low level drivers and design the boards. The rpi lets random web-only devs fumble their way through hardware development using whatever GitHub Python libraries they can find. If you only need a hundred scooters it makes more sense to just yolo it and buy up the remaining supply of rpis to start your grift.
It negates the need for updates because it’s much less likely that BFU attacks are discovered that could compromise the phone.