Most of the "big" readers don't support microformats yet, but the #indieweb community is making some progress. Check out @aaronpk's post https://aaronparecki.com/2018/04/20/46/indieweb-reader-my-new-home-on-the-internet.
I use https://granary.io to convert my h-feed to Atom. It's more DRY than maintaining a separate XML file.
Responses
★ Tim Rühsen, Russell Vea