I believe you meant to add “in Starting Configuration”. Nothing says you can’t drop stuff out over the bumpers after match start… I’ve seen some interesting things.
Nothing says you can’t drop a bumper that isn’t a BUMPER over the frame perimeter after match start, either. It just has to stay tucked within the frame perimeter until then.
And during the match, I suppose the non-BUMPER might fall off, and not draw G104 disablement. That would sure confuse the referees.
Trust me, the refs wouldn’t be confused by that one. They’d KNOW which robot it came off of and hand it right back after the match. Done that for random gears and such-like, you think a well-marked bumper will be a problem?
Unless 900 was also in the match, in which case they’d get it.
I’ve seen a few tricks to make things easier. The apparent bolt taped to the frame didn’t make the cut… a strip of what looked like duct-tape fabric seemed to do OK. A few teams had low-down bumper-crossers that helped pull.