The “still loading” screen on the latest beta solves the problem described in I got trapped by a really slow site but I think your comment rightly points out that it’s triggered it a tiny bit too early. I’m pushing a new beta to fix another subtle bug, and will adjust the timing of the loading screen as well, showing it only a few seconds later. Its purpose really is just as a fallback on the rare occasion a site loads way too slowly or doesn’t load at all.
Edit: new beta build 163 should be out.