So, when will Google roll out signed exchanges for plain HTML content? That's much more interesting, and if combined with e.g. a restriction such as a Lighthous

So, when will Google roll out signed exchanges for plain HTML content? That's much more interesting, and if combined with e.g. a restriction such as a Lighthouse speed score of > 60, it'd be in all measurable ways better than AMP. Faster than AMP, more open than AMP, and all the benefits of AMP.