I don't think CondeNast cares.
replyDo any of the cbz readers handle jpeg2000? It makes a big difference in filesize without any quality degradation. Like 40% smaller, maybe more in some cases. You should tinker with that if you have the time.
Okular handles cbz that contain jxl with no issue. (IIUC both archive format and image format support is provided via a pluggable extension system but I don't recall the details because my setup has "just worked" for a very long time now.)
replyAlso FYI you can use mupdf to read cbz archives although I don't personally recommend it for that usecase.