Here are a couple of macros that leverage AppleScript to accomplish some basic Music tasks without having to interface with the Music app UI directly.
The "Display" macro is self-explanatory. The "Add" macro gets a list of your playlists and prompts you to choose one from the list. Then it adds the currently playing track to the chosen playlist.
Each macro displays a AppleScript generated notification dialog which persists until you hit spacebar or enter, or until a few seconds have elapsed, whichever comes first. You can adjust how many seconds by changing the number after "giving up after" in the AppleScript. You can replace that with the KM notification if you like. I like customizing my notifications with AS.
Important: The "Add Current Track to Playlist" macro should be invoked only while music from your Music Library, and not from Apple Music, is playing. If you trigger it while playing a track in Apple Music, you'll get an error. The track needs to be in your Music Library in order for this macro to be able to add it to one of your playlists.
The "Display Current Track" macro will work with any track, including a track in Apple Music.
(These macros are uploaded in a disabled state. You'll need to enable them after you install them in KM.)
DISPLAY CURRENT TRACK.kmmacros (2.5 KB)
And for good measure, here is an Applescript for adding the currently playing Apple Music track to your library: