On XA2 (with 4.3 at least), you have to backup partition #76.
I did it as proposed by DrYak in the [xa2] Full-backup in terminal thread (click “see more comments” near the end)).
Restoring it perfectly works except fingerprints as in Backup/Restore, where are fingerprints stored?, because I restored on another device. (and maybe wifi, I don’t remember).
EDIT: Reflash the same OS as the backup was made on before to restore, to be sure every other partition is ok too.
I also had
/dev/mmcblk0rpmb: read failed after 0 of 4096 at 0: Input/output error
/dev/mmcblk0rpmb: read failed after 0 of 4096 at 4128768: Input/output error
/dev/mmcblk0rpmb: read failed after 0 of 4096 at 4186112: Input/output error
/dev/mmcblk0rpmb: read failed after 0 of 4096 at 4096: Input/output error
even after having reslashed Android, then SFos, then boot in recovery mode.
Any idea if it is a problem?