My collection is around 20K tracks. It takes the RPi3 approx 12 hours to scan the collection. Much better and quicker results using two or three 256GB USB sticks which are now affordable at £50 or Euros each.
I believe the following fairly simple change would make a significant difference to the browser page switching time :-
For large collections I don’t think it makes much sense to list all the Artists, Albums AND Tracks at the genre level. I think it would speed up access time a lot if the track listing was dropped at this level of the menu - keep the track listings for the Artist and Album levels of the browser.
Also when rescanning the library the artist/album/track times should reset to zero at the start of the rescan - currently it doesn’t. Resetting the counters would help you know that the rescan is happening. At the moment these numbers only update once the totals exceed their previous values.
Lastly, a minor point, I think it would be good to have “Playing…By…From…” at the top of the pages in a larger point setting of the font.
Thanks for an excellent, open ended and sourced player.