Thanks for the update @maxmp!
It's looking good so far but I've found one issue with Album Artists list. It seems like Poweramp marks any file without Album Artists tag as a track with unknown album and it carries that information to the main player screen (only that part, somewhere else shows the correct Artist). I know it can be fixed by filling the missing Album Artists tag but I hope it can fall back to Artists tag when Album Artists are empty/unavailable. Join Albums option inside Settings > Library > Lists does not do anything with this issue.
These are the screenshots of the behavior I just stated above
In Artist > Albums list: https://i.imgur.com/FkbsAaM.png
Main screen when played from Artist > Albums list: https://i.imgur.com/2YcIYCg.png
In Album Artists > Artists > Unknown Artist list: http:// https://i.imgur.com/QKnd1Kn.png
Main screen when played from Album Artists > Artists > Unknown Artist list: https://i.imgur.com/Va3Ag0m.png