I do. On all my devices. The base of android is indeed open source and is called AOSP (Android Open Source Project). Many, many alternative distros, called ROMs, are made from AOSP and have zero closed source or proprietary google code.
I run LineageOS on my main phone, and different roms on my backup phone and tablet. The easiest devices to install alt roms on are actually google’s own pixel phones, as well as google tablets. Very easy to load an alt rom on them.
There are also some OS options not based on AOSP. 13 Open Source Mobile OS Alternatives to Android
Dude, the FW16 isn’t even out yet.
Every ounce of effort right now is going to the actual laptop, not a nice-to-have bonus. Shipping dates FW 16 - #199 by Jordan_Long Why would single key modules be released before the laptop itself?
I believe Cherry MX ULP could be done. It’s not that they absolutely can’t fit, just that there’s precious little room for the PCB and the keycaps. One would have to get unconventional, especially for the keycaps.
Or one could probably shim the hinges up a smidge and give yourself more room.