Hello. First of all, I'm very happy with UAPP, so let's get that straight!
But I thought I'd list my niggles:
1) Tidal: doesn't have "My Artists" option.
2) Tidal: Search for artist (ie Supertramp) which lists albums, select an album, start playing a song. At that point there is then no way to backup to the list of artist's albums. Instead, you have to start the search over again.
3) When you exit and re-enter UAPP, the volume doesn't seem to default to the last volume used, but instead seems to default to maximum. I haven't quite figured out what's going on, but I have blasted my ears a few times, so I'm having to be careful.