The real plane has heading information on the backup attitude indicator:
I have added it as well:
You can download it here (extract to Community folder):
cc @PharaohEo you may like to integrate this into your mod or otherwise be interested.
This isn’t much but I also do not know which other modes the backup attitude indicator in the A5 supports. We could remap the brightness buttons to switch between modes and have a much more powerful screen, I believe.