I haven't, but then again the fogging along the top has never gotten bad enough to where it's actually blocking my vision (unlike my old glasses.) I can see it along the upper portion of my sight line, but my straight-ahead vision is unimpeded.

Not sure if removing a piece of foam a the top would help as the edge of the goggles would still be up under my helmet. Interestingly enough my old glasses leaked air around every edge and were much worse for icing. So the foam seal may actually be what's keeping them from icing as much.