BOOT UI can be installed on pie

[mgood7123]

backup a PIE rom via PDB
(if using DBP WITHOUT BOOT UI, then backup ROM's via DPB:

ROMS > 
    select your ROM
        BACKUP ROM > DATA, SYSTEM, CACHE
    repeat for all other ROMS you want in BOOT UI

)
(optional: backup current rom via TWRP (as a full backup) incase BOOT UI fails to install for a backed up ROM)
flash a rom that is android 8.1/8.0 (Oreo) or below (I flashed 7.1)
install boot UI
update ramdisk
flash a backed up PIE rom (BACKED UP by DBP, NOT twrp)
update its RAMDISK
reboot