[GaryVoshol]

IMO it meets the letter of the rule. Maybe not what they expected to see, but there is no rule (yet) against it.

I question the wisdom of the design. Mount your bumper. Now kick it down near the bottom. Repeat several times. Does the hardware pull from the wood? Do the mounting brackets break? Does the wood splinter near the top?

If you've got the weight allowance, I'd try to attach several vertical standoffs to the bottom of your frame to give the bumper some additional backup.