Offline usecase for music

[TheDreadPirate]

The only music apps I am familiar with are Finamp (FOSS) and Symfonium (paid). They each handle being "offline" differently.

Finamp's offline mode is a true offline mode. The only things that exist are the tracks you downloaded. Likes/favorite is unavailable and so is playlist management of any kind, even if you try to add tracks you downloaded to a playlist.

Symfonium maintains a local database of your media so it has more robust options for offline management. It does allow you to like/favorite offline and it will sync the changes when it is online with your Jellyfin server again. You can also import playlists from Jellyfin to Symfonium and manage while offline. I'm not sure if I'm just being impatient, but I have to push sync playlist changes to the server.

For your needs, it sounds like Symfonium meets them.