I often have spotify playing while doing different stuff "afk". When I do so I mostly let my favorite playlist's radio play and hunt for new tracks. But it's -sometimes more, sometimes less- frustrating to stop what I'm doing just to add the playing track to my playlist.
Something like "cmd + '+'" to add the track to the current playlist (the one the radio is based on).
would be really awesome
(I guess Shortcuts in general would be a great deal!)