And the very first reason they state is to speed up loading by using hidden portals, and then activating them on demand. When you first stated use case is a ha

And the very first reason they state is to speed up loading by using hidden portals, and then activating them on demand. When you first stated use case is a hack around what the spec really is supposed to provide, you have an issue. If you want to speed up rendering of links, create a spec designed and optimised to speed up rendering of links. Not something that will clutter the DOM, then need additional CSS rules to hide what your new element is supposed to do altogether. All of that to sort of arrive to your primary use case.