[GaryVoshol]

Notice that a portion of the "interior bumper-like structure" extends beyond the Frame Perimeter - that's the primary reason it's not OK. The section of the actual Bumper that extends partially across the cutout is also troublesome; I don't know if the rules address it as "unsupported" or not.

And as noted above, any bumper-like structures that do not qualify as Bumpers must be counted in size and weight.