I a future there will be that feature, but now it would create a big problem to the way it does sort files, so I have to think the most flexible way to solve this problem.
Personally i do prefer having different chapters into different pdfs
First I want (and need) to focus on the output quality that still need work, but for that i do need someone with an iliad or a sony and a digital camera, to help me figure out how the changes reflect on the readers.