I too was unsatisfied with jellyfin’s music handling. Not only was the website disorganized and bad at using the built-in album art, but all the android music players i could find for it were also barely usable as well.
I can’t use musicbee because it’s windows only. I still want synchronized play history, metadata updates, and everything between my phone, pc, and mp3 player so a single OS software was out of the question.
I use a combination of beets, navidrome, and tempo. Beets is the metadata manager; once i’ve beet imported an album, it’s ready for navidrome to pick it up and serve it to any of my devices. (I have a custom sync script for my mp3 player that does the same). Navidome serves the music to any connected devices, converts it on the fly to lower quality (for low speed phone network situations) and also keeps track of my play counts, and my playlists for me. It’s not nearly as complicated as some of the other setups, which I also prefer.
I use tempo on my phone to connect to navidrome on the go and it has worked out incredibly well so far.
Terramaster had some pretty gnarly security issues that they badly handled in the past. No big deal if you keep it walled off from the internet, but their software would never let you know it should be kept away from any internet access.
Also, if you get one of their units that has an ARM chip inside instead of an intel one, there is basically no chance you’re ever going to be able to use anything other than the software that they have by default. This makes the security issues impossible to resolve without completely removing internet access to the device.