Just commenting to add my support to this request - being able to draft in markdown would open up a lot of workflow possibilities for me and the teams I manage. Baseline features to make this useful to me:
Heading paragraph styles (#, ##, ###, etc. - as well as ---- and ==== markup for h1 and h2)
Bold and Italic character styles
Block quote paragraph style
Tables would be great but I know they're not standard across all Markdown flavors, and Affinity Publisher handles tables a little differently such that they would need special consideration.
I know there's other things that would need to be considered, but if I had those things my workflow would be improved dramatically.
Currently it is not possible to adjust the word kerning on a line per line basis. It is only possible to apply it on a whole paragraph by selecting a justified text block and adjusting the settings in the paragraph section of the style panel. This task is common in editorial design work, when you want fine control on a text block.
InDesign supports this kind of control.
Keep up the good work!