In reply to
.Now I don’t use Gutenberg—I let the Micropub plugin generate the necessary markup, or hand-code it inside WP Admin—because my site’s actual front end isn’t a WordPress app, but I do on this other blog of mine, where I’m also running https://github.com/janboddez/indieweb-custom-post-types, which registers just Note and Like CPTs and makes Micropub apply them. Very simple, extremely flexible.