I've been trying to get this working since the Beta of Netlify plugins, and along comes Mark with a fully working example 😂 Definitely want to look into the source code (GitHub) and see if I can get this running here. Also, clever way of doing a quick feed comparison (I think I might try to identify updated database entries somehow, but then I am running a server, just not using it 😁):

I wrote build plugin inside the repo for this site which makes a request for the atom feed of my site before the build is run, and compares it to the generated atom feed after.