I started writing the book in Obsidian, but realized I needed something a little better. So, I took it to Scrivener, which is where the first draft was completely developed (it can maintain references and a TOC somewhat).

But once I needed editors, it had to be in Word and all of the references needed to be rebuilt when that was completed. It's now in a contractor's hands, using some book making software (not even sure which, I think an Adobe product).

So, yeah.