I have audiobookshelf, along with readarr for downloading and the two have a totally compatible naming structure configured so it works like a dream. Not 100% sure it was that way at default or if I had to configure readarr to match what audiobookshelf needed.
It’s annoying it won’t subfolder the server under domain for reverse proxy, but that’s not too much of a worry.
UK here.
Yes, 2 or 3 pound. Typically that’s about 10%.
I refer to it as the lazy tax.