Yep, you're right.
I think the only time that line would do anything is if you put a status change at the end of the file (the way it is in my version would report a 0 for that status), and now…
The += 0 is intentional.
If this status hasn't been used in this chapter yet it's no different from = 0, mainly here to initialize.
If this status has been used, it leaves it…
Yeah, I missed that.
Unfortunately, from a quick look, all those modules are meant as extensions for markdown conversion, not sure if you can make them output markdown.
I don't feel strongly about this either. Basically I wanted to avoid a mandatory dependency, note that the dependency is loaded only if the flag is set.
I meant optional output data, but agreed, optional flags is a better way of phrasing it.