I just went through this and tried quite a few Navidrome clients before settling on Plexamp.
I wanted to like Navidrome because it’s more forgiving with your tagging/organization, particularly with compilations. It reads the compilations ID3 tag and puts all tracks with the same album title and that tag in one album, which is super simple.
Plex is far more picky with tagging/structure. But the clients for Plexamp are just so much better, imo.
So I just eventually sucked it up and spent days retagging my MP3 collection and moving files around to make it work with Plex. It sucked but it was worth it.
I'm confused by Synology's OS and how you actually view the SMART report but it just says "Healthy" and now it isn't even showing the bad sectors anymore...