It didn't used to matter much what #YouTubeAccount I was logged in as, but now I'm trying to stay logged in to #YouTubePremium account.

I would definitely appreciate it if I could #sortPlaylists by #mostUsed. They seem to be be sorted by most recent or alphabetical. It's easier when adding to a playlists because it only shows playlists you are a collaborater on, but its then hard to find the playlist to listen to even though you just added to it.