I've seen this level mentioned in a couple threads, how there's a potential for placing the beastman in such a way as to block passage except for those with acrobat, etc. I don't see it, though. The existing rubble is diagonally on a corner, which I thought you were able to pass through (open route #1). If you stand him next to that rubble to block the straight movement, you also have diagonal passage between him and the opposite corner (route#2). Is there a spot I don't see?

Or are they talking about dropping a crushing block so as to block route #2 between the beastman and the hallway beyond, combined with not actually being able to get through route#1? I guess I have two questions then, one being "where's the cheese?" and one being "Can you move between a rubble and a corner when they join diagonally?"

There was some debate in this dungeon referring to placing a Crushing block within appropriate range of the fountain. This would enable the (in that case unkillable) beastman to block the path to the red rune door for any party without Acrobat, Fly or Knockback weapons - there´s the cheese.

The FAQ ruled that the heros may move through the beastman in that case - no more cheese.

And yes, you may move diagonally between any combination of two movement blocking obstacles/figures/corners.