Does anyone actually use `ox-rss.el` the way it's intended? It expects one monolithic Org file containing all posts, all of which are top-level headings.
If you want your posts to be individual Org files, it seems like you have to generate a special sitemap file (separate from the one used to display the post listing) just to give `ox-rss` the list of posts in the format it expects.
Not impossible, but definitely not streamlined.