Yeah, @dluvian was talking about that. It'd be a simple script, really, so long as the document had only 2 levels: header and content-articles (which most would). 

The 30040 contains the ePub metadata and the list of source files for the document, then you just have to find all the json files on the relays, extract them all into one markdown file, and convert them with pandoc.

And the breakdown would just go the other way around. We're actually usually starting with one markdown file, so that's actually how we're doing it, now, using a script to split it up into 30040 header and 30041 sub-events. 

 ...I don't know how to pandoc 

 You don't have to. 😂 We're going to have a button for that. 

 Awesome