Everything I do is manual, I don’t really have duplicates unless I get singles then get the album once it releases. Even then, unless the single comes with extra bonus tracks (seems to be a lost past time, never see this anymore) I will delete the singles after.
Here is the forum post I originally found years ago to setup music picard to tag multiple genres, which is the only setup that I have that took extra effort and not just use out of the box defaults.
I used to use Subsonic, but it’s become too outdated for me sadly. I switched to a fork Navidrome which updates a few times a year and enjoy the improvements it’s been providing. I use it with the mobile app Symfonium and love that they are both improving the API to add additional features and options over what Subsonic offered. I run it on my Synology in Docker so you should have no issues either.
https://github.com/navidrome/navidrome