SFOS on Xperia 10 II under Android 12?

I bought another (used) Xperia 10 II to replace my dead 10 II (due to HW fault) that had worked quite well for me, while awaiting sorting out the issues regarding 10 III.
However, the Xp 10 II that I bought had been updated to Android 12, (discovered that too late …), which leaves me with the following questions:

  1. Is there any use at all to try to install SFOS on the 10 II phone in current state, as Jolla under “Required stock Android version” states “Android 11 (10 is ok)” for this phone, (and don’t open up for “12 is ok” as Jolla does for 10 III)?

  2. Where can I find info on how to downgrade the phone from Android 12 to 11?

(3. Can I expect to be able to re-establish the data content on a phone running SF 4.5 from a back-up made under 4.4?)

Xperia 10 ii and Android 12 according to this thread people had luck with flashing over android 12, but there are steps mentioned how to get 11. IIRC you need the Emma Sony tool for that.

  1. The thread that @PeperJohnny refered to is a good start
  2. Reinstalling Sailfish OS | Sailfish OS Documentation
    Follow the Reverting Xperia back to Android OS
  3. A backup is generally forward compatible (4.4 to 4.5)
    Sidenote: Read here what a backup contains: Backup and Restore | Sailfish OS Documentation

@PeperJohnny @emva Thanks for the responses that clarified various matters for me – and gave me confidence to try to install SF 4.5 on my Xp 10 II without the hassle of downgrading to Android 12.