It seems the kernel is too old, and lacks capabilities, so upower doesn't work as with #36, but is a likely good first step.

Jul 07 23:35:27 nixos systemd[1]: Starting Daemon for power management...
Jul 07 23:35:27 nixos systemd[920]: upower.service: Failed to drop capabilities: Operation not permitted
Jul 07 23:35:27 nixos systemd[920]: upower.service: Failed at step CAPABILITIES spawning /nix/store/lkwf8bsfy0kn0g5mahhijr1lrh43h3mw-upower-0.99.11/libexec/upowerd: Operation not permitted
Jul 07 23:35:27 nixos systemd[1]: upower.service: Main process exited, code=exited, status=218/CAPABILITIES
Jul 07 23:35:27 nixos systemd[1]: upower.service: Failed with result 'exit-code'.
Jul 07 23:35:27 nixos systemd[1]: Failed to start Daemon for power management.
Jul 07 23:35:27 nixos systemd[1]: upower.service: Service RestartSec=100ms expired, scheduling restart.

Something will need to be figured out about that.

There's a bunch to unpack.

The patches are mostly reverts of spooky qualcomm, Android or asus code. When not spooky, it's simply not written with USER_NS in mind.

The features disabled in config.aarch64 are features added to the kernel for Android, mostly network bandwidth accounting. Those features, too, weren't built with USER_NS in mind. Disabling them is easier than surgically removing the commits for now.

In addition to all that, the kernel has been updated to the latest revision from the lineageos repository. I figured I never did it since initially porting the device as a test way back when.