Earlier quoted context omitted.
I had lots of luck with https://github.com/phhusson/treble_experimentations/wiki on Mi Max 3. In general any recent phone should work with these ROMs. On Mi Max 3 it works perfectly with only a few tweaks after flashing. https://github.com/phhusson/treble_experimentations/issues/1... This one, and one more for Bluetooth audio
Fingerprint reader: Works Broken on Always on Display (turn screen on first) Kind of a big deal. Do you still need to apply to unlock your own device and hope they let you?
That the fingerprint reader doesn't work is a feature, not a bug. Fingerprints are the worst passwords, as they are easily obtained/faked and cannot be changed.
This tendency to embed biometric sensors in consumer devices is hurting users and hurting security. Only cops and psychopaths find any sort of advantage in that.