Quote Originally Posted by Martinm210 View Post
I just see this as another possible optimization. The radiator manufacturers could either build in their own bypasses to emphasize performance in one area, or the user could do it with plumbing/valves
Maybe this is the reason for the gap inside the TC rads?

Now that I think about it some more, any physical deformation that interferes with low-speed fan cooling, should only be magnified with the high-speed fans. Which doesn't seem to be happening.