I can confirm and I do use this feature of jellyfin. It works great. The reader is unusable. I use Librera for reading. It’s great, free, and open source.
So my flow is biblio, mam, library Genesis, Anna’s. Then to jellyfin folder that it reads automatically. Then I can download that to any device connected to the jellyfin server. Local is easy, abroad through tailscale.
I use jellyfin to host everything; movies, shows, books. It can tag matadata and id most books fairly well. But do not use it’s built in reader. I don’t know about comics though. I can then easily download whatever book to any device connected to the jellyfin server and use local software to read it.
I usually just use librera reader as it’s open source and highly customizable. But it does have it’s glitches.