Thanks, that's kind of what my research indicated to me as well, no real root access, and no boot access like on my android phone, so OS backup is most likely not viable short of booting from USB, and I've found no options for that either......
Like you, I have also copied the "scan" folder to the sd card and then made another dupe to one of my external backup hard drives.
On yours, have you noticed it taking longer to boot and load the "MaxiDas" app when your SD card is installed?
Without the external SD card installed, it can boot and be active in a bit under 1 minute.
With the external SD card installed it will boot just as fast to the lock screen, but the MaxiDas app doesn't load right away, a pop-up box says "SD card not found" then after another 1 minute(I'm guessing after the OS sorts out and mounts the external SD card, the app will load and it runs fine.
I've decided to use it most of the time without the external SD card installed, and only put it in when I think I may need it.
Scott.