Yeah, that's what we're building, next version.

That's why we choose to do the 30041 events with Asciidoc, as that's a markup language that allows you to define everything you need to generate an ePUB (or LaTeX, PDF, AsciiMath, etc.), like cover image, type (Bible, scientific, novel, code, audiobook, etc.) for the style-sheets, summary, edition info, etc.

We're using the Asciidoctor platform, which already contains the functionality to convert and export. Implementing that has taken a loooong time, but it was worth it.

But we're also going to make an ePaper reader, so that you can view the books directly as notes, without having to convert. That means that you can then keep the cool Nostr functionality, like highlights and bookmarks and zaps. Or you can review a book, by replying to the 30040 with a kind 1111, and then all of your frens see your review, when they look at the book's index card. Or zap-to-decrypt a book.

That sort of thing.