Indeed I have Funkwhale on the radar, but tbh I don't have a strong use case for streaming at home. Was thinking about putting it on my rPi -- but in the end it's even easier to just stream from my iPhone through Bluetooth (or a good old jack).
My priority is to build a clean library with beets, transcode it in mp3 and feed it to iTunes, to have it on my iPhone & iPod.
Maybe time to give Plex a try for this.
I run all songs / albums through MusicBrainz Picard before putting them in the music directory structure so they're fully tagged. It only misses some of the more local / esoteric stuff I've got.
only downside is that if you have a really large music library you will have to use syncignore filters to stop some things syncing to devices that don't have enough space.