Looks like superfeedr does what it says on the tin but I need to understand that API to make it practical.
How quick for this post
How quickly will this post be found, real time?
Real Time RSS PubSubHubBub
I am trying out Superfeeder right now. How long before this blog posts is found and I am notified. Real time, 1 minute time, 10 minute time. I’ll post the answer later.