unfortunately not one I can think of without htmx being baked in to HTML
which, I think should be the case: I don't think htmx should have to exist, I think this is just how HTML should work. That could address a lot of accessibility and progressive enhancment issues as well.
I have no idea how one would go about doing this, but I'm curious if you have pursued that option? Getting the functionality of HTMX into the HTML standard?