Understanding that I am one of the 1% that actually listens to classical music, I have a problem with the search sort.
I have arranged my library with a folder structure of composer -- album. That works just fine in mobile. But.... For each album, I have tags work -- title. Work is a custom tag. This is a disaster in mobile. Because mobile doesn't recognize Work, it sorts by title. So, on a baroque concerto album, I get a dozen "Allegro" followed by half a dozen "Largo". This because of the standard paradigm of Artist/Album/Song.
Is there any way to get mobile to recognize a custom tag "Work, or at least sort by Composer/Album/Track?
It may not be ideal, but you could sort it by composer, then by album, and move your %work% information to the beginning of the %title% field.
If you have MP3Tag it's easily done. Click on "tag to tag" and define %title% as (%work% %title) (parentheses for clarity; don't type them). I don't know 100% whether it will let you replace the %title% information essentially with itself so this may not work -- but I see no reason it shouldn't.
Ideally you'd have organized your files this way from the start but with MP3Tag it should be quick and easy. Unless it's not.
I have spend untold hours tagging my 1000+ album library to display composer/work/movement in the real FB2000. I am not going to spend a minute to retag everything so it will work on mobile. If I want to listen to something on my phone, I'll use YouTube. the YT search works the way classical music has to be sorted.