OS ≠ user interface.Use whatever OS that runs Kodi or some other user interface the best (with privacy also being considered to be best).
The more important question is, are they running mainline Linux, close to mainline Linux (like Raspberry Pi, or outdated much modified unmaintainable vendor and device specific fork (like Android phones do).
If have open port than I2P is faster (still not fast, but much better) because you actively contribute to the network.
No demands, just a personal wishlist:Stable releaseFederationPrivate/locked/encrypted albumsHiding photos from album from timelineDropping Redis dependency (not open source)Better editorSome (unofficial) Linux mobile client happening
Wow, really great idea and looks so simple to use.