Here are some interesting scripts that aim to help with organizing a music library and specific use cases. Not all may be plex specific, the scripts just caught my eye. Caveat: I haven't tried them out myself unless noted. If you try them, please leave a comment to help others. I plan to update this list from time to time.
Chromatix: Plexamp is an excellent mobile app which can run on desktops - but is not good at that. Chromatix is my favorite when I listen to a specific album. It has a nice UI with a lot of features - not the DJ's and the other stuff dependent ons sonic analysis though. In use.
Plex-Music-Organizer: Exporting Plex music metadata and update tags from CSV within the database
AudioMuse AI: Sonic analysis and AI-powered clustering to create smart, tempo and mood-based playlists within Jellyfin and Navidrome API.
Audiograde: Picks a random album, plays it to help rating its songs.
