We don't support that currently, but would love to see examples where you disagree with the chapters so we can figure out the best interface

You can regenerate the chapters anytime, but it might lead to similar results as the first time

We're also planning on adding functionality to support some sort of CHAPTERS.md file that lets you specify how you want things broken down!

CHAPTERS.md sounds like a good idea for when the auto-grouping doesn't match the actual structure of the work. Looking forward to seeing it.