Unlike many Android phones that allow users to unlock the bootloader to install custom ROMs (like LineageOS), the KEY2 features a heavily encrypted bootloader. Hardware Root of Trust:
On official OS, you can swipe left to delete words or slide up/down on the keyboard to scroll. On a custom ROM, the keyboard is just 35 mechanical buttons. The capacitive touch layer has no driver in the Generic Kernel Image (GKI). Unless Qualcomm releases the source code (they won't), the "Magic Keyboard" is dead.