@kdakodiac
You could try https://github.com/qarmin/czkawka to find duplicates.

I got information that ListenBrainz is working on something that could be used for that as well. See https://github.com/metabrainz/troi-recommendation-playground
ListenBrainz is from MetaBrainz, the head of MusicBrainz (with picard and so on).

(I was not able to edit my first post)

Overview
I would like to suggest the addition of a "Intelligent Playlist" feature inspired by a similar functionality from the Guayadeque music player.

https://de.wikipedia.org/wiki/Guayadeque_(Audioplayer)

auf Last.fm basierte intelligente Ergänzung der Wiedergabeliste (sog. Smart-Mode, d. h. es werden weitere Lieder automatisch hinzugefügt)

Intelligent addition to the playlist based on Last.fm (so-called smart mode, i.e. additional songs are added automatically)

The feature would automatically add songs based on their similarity to the currently playing track. The proposed feature involves scanning the local library and utilizing last.fm "Similar Tracks" feature to identify and add songs that are similar to the current one.

Example
https://www.last.fm/music/Letzte+Instanz/_/Rapunzel

• Track: Letzte Instanz - Rapunzel
• Simlar Tracks: Schandmaul - Walpurigsnacht; Ignis Fatuu - Spiel des Lebens; Cultus Ferox - Goldene Zeiten

Implementation
According to https://github.com/anonbeat/Guayadeque, the player is written in C++, which might make it possible to utilize some of its existing code.

My limited understanding is that https://www.last.fm/api/show/track.getSimilar could be used for that feature.

Alterantives
I found another tool called https://github.com/teticio/Deej-AI that seems to scan the music and create a playlist from that rather than dynamically updating the playlist with similar tracks in real-time.

I think it might be unique addition to the player

Sync playlist to a file would be good. I want to use the player on my computer and put out a playlist and add the playist to my DLNA server so my Streaming box can pick up the playlist as well and i can play what i want and not just some random stuff.

Is there any update on that? I have tagged all my music with MusicBrainz Picard and i have multiple genres on basically all songs. I see there is a field named "Genre" and the smart playlist "contains" seems to work.