I did notice such a thing at the maximum size, but that was such an extreme condition I had thought it was happening by accident. So as far as I can tell, it effectively doesn't come into play, meanwhile as early as 200ft the character's punches start missing buildings. And as I test the collision tier thing now, I see it starts at around 900ft for the lowest tier of building. Ultimately, I think the gap there is too large. Game design-wise, I'd bring the thresholds a little closer to the 200ft size where punches miss at (compromise at 500ft?). Personally-wise, I'd just be happy with the cheat option.
On a bug reporting note, I noticed during testing that the police station can still block at max size. I can't tell if it's a certain side, certain damage model, or what, but it's certainly the police station.
I also noticed the character's collision is different between walking and standing. You can walk into and be blocked by a building, but if you stop walking you'll get closer to it. Hm, this is tricky to describe. Basically, the walking collision is bigger than the standing collision, which is an odd thing to see.