Just for some more clarification: Only the pink surfaces will be ignored?
After some playing, it seems, that simple crosses are fine, L-profiles and U-profiles most of the time too. Even simple cut outs. But beyond that the risk of not working anymore seems to rise drastically (like H-profile).
Some Test meshes, to find out, what works and what will cause trouble. One area was constantly pink, another one didn´t work properly for reflections.
Yep, an H-profile doesn´t work properly.