Logitech Media Server, followed by strawberry, quod libet, rhythmbox
Quod libet starts to act funny with 50,000 flac collections. Rhythmbox too. LMS is still chugging at 100k and I can get it on any room in the house, across 2 clients on computers, 2 on raspberry pi and my android phone. If I want to listen to 24/96+, Strawberry can handle it all although I haven't warmed up to the interface. Volumio sucks, it's way too slow.
https://www.washingtonexaminer.com/?p=2070915