Hi @kdjamesrd,
Please be sure to take a look at our video library, where we talk about exporting to markdown quite a bit, including the #, ##, ### outline structure.
Here is our latest: Tinderbox Meetup Saturday 27 JAN 24 Video: Blooms Taxonomy, Infocom, Markdown Export, Auto Numbering. You’ll find more if you search on the above template: Mastering Tinderbox: Training Videos (Complete List1).
@sazanamix and @mwra have done a nice job to show how you can build the YAML elements in to the header of the file.