Wasn't there a C-library for nostr?
I forgot the name...
But basically that plus this should make a highly customizeable rss-to-nostr setup possible - and reliable. Super minimal deps and a clean API.
Make it configure through environment variables and you may as well have a throw-away container to yeet into a kubernetes cluster or the likes that will continiously publish stuff - and since proxy support is effectively built in, could even go through tor and publish through it too. Or i2p... whichever.