[GregW11]

It probably wouldn't work even if "outer ege" were to include the inside of a U-shaped robot. Consider this: the last part of R11: The Bumper perimiter may extend up to but cannot exceed the maximum robot volume constraints defined in Rule R11. From what this says, if the inside edges of a U-shaped bot have to have bumpers too, most likely the perimeter wouldn't sufficiently cover them.