i should also add that both khatru and relayer ( https://github.com/fiatjaf ) have got little slots to let you put arbitrary web handlers in them to do such things as the http server you need for RSS documents, really you just need another process running that fields the updates and rewrides the static files that the webserver can serve)

i haven't done this terribly much with my fork of all this but i made it do some basic things, thanks to your nostrudel relay page showing the content of the normal https socket i put something in there