I ended up following the advice in this blog post (in french) https://arthurperret.fr/2019/03/07/le-diaporama-au-temps-du-balisage/
Basically going through Pandoc to convert the markdown to Reveal.js HTML. This adds a few bonuses like citations and fenced divs. You can pass the location of a central Reveal install as arg to Pandoc.
My build command looks like this:
-t revealjs -s
-V revealjs-url=/.../reveal.js ⬅️ cloned Reveal repo
Hometown is adapted from Mastodon, a decentralized social network with no ads, no corporate surveillance, and ethical design.