Apple and Qobuz both handled differently and both appear to work:
Apple allows for multiple booklets, perhaps to be included with groupings or subfolders (disc1, etc):

Qobuz, on the other hand, include an icon along with the album info (I couldn't find an image but here is a url):
https://play.qobuz.com/album/ys96i2ayewnpaBoth have their pros and cons. I imagine the qobuz approach would be easier to implement. The iTunes approach, on the other hand, I believe, offers more flexibility - ie booklets tied to groupings, multiple booklets tied to an album/box set, etc... the iTunes approach would also allow you to potentially manage the file name, the same track filenames are managed