Sorry for the very late reply, I live in the north of Poland, so not really close to Vienna, but this doesn't matter anymore as I've tried installing Sailfish OS x86 on the onda, and it booted fine, but the touchscreen wasn't working even after trying to install many different drivers. So I gave up and got a used Sony xperia 10 II, installed SFOS on that, and it's been working perfectly ever since.

Since the repo http://sfos.scanf.su/onda-v820w-v3/ needed to install SFOS 2.0.5.6 is not responding anymore, does anyone know of a mirror of it or at least happen to have the files?
The contents can still be seen here:
https://web.archive.org/web/20220401...onda-v820w-v3/

TheKit's compat repo is still available:
https://repo.sailfishos.org/obs/home.../compat-v820w/