AppleScript for Music.app: Trying to determine if there is a previous and next track in a playlist

Question

I am trying to modify the action of the previous track and next track commands to not take action if current track is the first or last track in the playlist. Present behavior is for play to stop and "current playlist" to become invalid if command goes off either end of the end of the playlist. (Using for controlling Music.app with Bitfocus Companion and Stream Deck controllers triggering AppleScripts)

I've used the ideas from and have it working well for reasonably sized playlists.

However, when working with a very large main library "Music" playlist the "tracks of current playlist" reference takes much to long to be useful. Since the Music library seems to be treated as one big playlist I'm guessing that the search scheme used in the above will not be limited to what's actually in the main window as I would like (haven't tested this because with a library approaching 40K tracks I don't have the patience).

So beyond looking for any general ideas, I'm wondering if there is a way to get at the ids (or any other useful identifiers) for the tracks presently displayed the main library window?

Thanks

Just a thought: maybe someone with more cred could add a tag for Music.app as actual iTunes hasn't been a thing for some time.