• Access to my entire music library remotely
• A directory structure view, rather than just Album/Artist/Genre views
• Transcoding while streaming to minimize mobile data usage
• Syncing parts of my library for offline usage

FWIW, you can partially hit most of these with Navidrome with another frontend. I like using Symfonium (android) which allows local downloading, and has a directory view. I don’t think it would work offline though for the directory view. I don’t know about caching/downloading on desktop though; feishin is my favorite desktop frontend, but I don’t think it has a DL/play from DL feature.

The above is only partial. Thank you for your work and sharing. I think the discouraging comments miss that this was a passion project of yours to fill your own use case. Good work!