I was surprised to see this functionality and tried it - it does technically work… but for authoring, the formatting tools don’t include styles (eg H1), just in-line formatting (bold, etc). I looked at the HTML output, and it added quite a bit of junk. Since TextEdit is quite basic, I disqualified it for this mission- as I’m looking for an authoring environment that I can comfortably & productively “live in” for an hour or two a day while writing. TextEdit’s HTMl mode seems more of a tacked on feature…