Often I just want a few songs to be played. Especially since I don't have playlist one mobile because it's to cumbersome to create them. But there's no practical way to do so.
An "add to playback queue" feature would definitely help.
Also it would help if the playlist features were more capable. The "add to" feature only allows one playlist (the last used?) so essentially random. The create new one doesn't allow changing the playlist name, so I get playlist with titles that have little to do with the content.

Both the playback queue and playlist selection would be great, one transient the other more permanent.