I agree with most of that ...
... but I think if we're going to take an evidence-based (what else?) approach to education we need a better basis than the statement "Grammar schools worked" - it is at least arguable that they didn't.
I think Grammar Schools made the usual mistake ... "we need to make special provision for the academically brightest". Actually, we don't: they will thrive almost anyway, even if homeschooled.
We need to remove the disruptive element: not by weeding them out by examinations but by providing the learning opportunities which will cause them to self select alternatives, and go to learn other useful abilities more relevant to themselves rather than annoying, or even bullying, the nerds.