I have been using Volumio - now version 2,917 - on Raspberry Pi 3B + for a long time and I am very satisfied. I have a large collection of flac files stored on the SSD drive and the only thing that bothers me about your application is the play function on the left side in the circle - when I’m in the Music Library. Namely, when it is selected on an individual music file, then the entire folder goes to the queue. This is especially inconvenient if you select a file that is outside of all folders then all the files on the SSD go to queue! Is that necessary. I see that hasn’t changed in your beta version of Volumio 3 either.
Best regards Dusan