What I think after looking at these numbers is that we need to take the nuclear option - a native (no web stack at all) code review client. Seconds (times 100 or so for one larger review) are not in any way an acceptable order of magnitude to discuss performance of a front-end for editing tens of kilobytes of text. And the slow, annoying click orgy to fold out more common code, a misfeature needed just to work around loading syntax-highlighted text being insanely slow. Git is very fast, text editing is very fast, bullshit frameworks are slow.

I don't think that it would take great contortions to implement a HTML + JS frontend that's an order of magnitude faster than the current crapola, but in practice it... just doesn't seem to happen.