On jamstack.org's list of static generators[0] you can filter by template language. For "R markdown" it only has: Bookdown[1], Rmarkdown as you mentioned, and Blogdown[2].

I've never looked at R markdown before. Thanks for sending me down the rabbit hole with Bookdown. It might solve one of the questions I'm currently thinking about.

[0]: https://jamstack.org/generators/ [1]: https://bookdown.org/ [2]: https://bookdown.org/yihui/blogdown