As you already have some familiarity with asciidoc/pandoc, then I would definitely recommend workflows where the output is MMD (which does support Pandoc).
Fundamentally, you want to use Styles and Section Types which the compiler will be able to transform to markdown. This can then be used by Pandoc for any final outputs. My usual workflow uses Pandoc and a management tool called pandocomatic: Scrivomatic: Scrivener & Pandoc{omatic} # | scrivomatic — but it does require some setup. But even if you don’t install any tools to compile yourself, you can still look at the document and compiler settings to get the idea of how to hook up styles and section types to flexibly structure your markdown. The resultant PDF for that workflow: scrivomatic/workflow.pdf at master · iandol/scrivomatic · GitHub – template: Scrivomatic
Quarto is a newer opinionated publishing system built on Pandoc, and it also integrates really nicely into Scrivener: Scrivener + Quarto: a technical/academic publishing workflow — there should be less setup, for basic workflows that do not use dynamic figures (you can run R, mermaid to build figures, but this is optional), only Quarto needs to be installed. Again, install the template and have a look at how it is setup, you can compare it to the sample PDF: scrivomatic/Quarto.pdf at master · iandol/scrivomatic · GitHub – template: Scrivener + Quarto
Download the .scrivtemplate files and then install them into scrivener from the New Project… dialog