What does "HTMX support" even supposed to mean? HTMX is a drop-in library. Literally any html file "supports" HTMX.
You're right – HTMX works everywhere by default.
By “HTMX support” I just mean: the JS logic in components (e.g. tooltips, modals) auto-reinitializes after HTMX swaps.
So you can use components inside HTMX-driven UIs without worrying about broken behavior.