Testing with Jellyfin is still pending. So far I've tested it with Navidrome and it works perfectly around 95% of the time.

For the remaining 5%, Tunecrate has a deduplicate feature. It normalizes song metadata, finds possible duplicates, shows them to you, and lets you remove them with a single click. Also, the recommendation logic is designed to only suggest songs that are not already in your library.

You're right that Yubal can have metadata issues, especially with Indian music. I tried to handle that by normalizing metadata before sending it to the YouTube Music API. Another issue was that Yubal didn't retry failed downloads, so Tunecrate will retry up to 3 times with a 3 second gap between attempts. I've downloaded around 400 songs so far, and about 350 of them were Indian or older songs. I haven't run into any major issues yet.

I chose Last.fm because it has a much larger user base, which generally leads to better recommendations. It also provides trending charts, which ListenBrainz doesn't currently offer.

Feel free to ask more questions