Installed your image, Chris, and so far it seems to be working. The backup functionality is now usable (in Settings > System) and I was able to create a backup on a USB stick.
But I guess I have to let the FP2 cool down a bit before testing to restore the backup after a clean install with wipe.
Edit: too bad that so many apps don’t allow a backup 
Edit2: I’ve done a factory reset to test the restore, but I don’t find a way where to start the restore process. Looking at this issue it seems it’s supposed to be part of the setup wizard of the OS, but I didn’t notice any…