The upshot of this is that progressive-enhancing custom-elements have to be carefully defined or they won't work at all.
It's somewhat amazing to me how unclearly documented WebComponents are, given how long they've been around, AND how unclear it is how to use them.
The guy who was a big part of it toots A LOT about React sucks, send HTML, use progressive enhancement, but then touts his company's WebComponents that render in browser, so I just don't know
https://ruby.social/@davetron5000/112819922667457514