[EricH]

Sunshine, it's not illegal because there's a cutout. It's illegal because a short distance of frame perimeter (which, I remind you, is independent of cutouts) has no bumpers on it, and the rule says

BUMPERS must provide complete protection of the entire FRAME PERIMETER of the ROBOT (i.e. BUMPERS must wrap entirely around the ROBOT).

(emphasis mine)

If it were something like 1/4", you might have a case, as normal bumper joints are nearly that big. But to be big enough to let an arm out, it's almost got to be several inches. Try being the LRI who lets it through because it's protected despite the gap, only to have every other team at the event complain that that team just got a competitive advantage!

Cutouts were permitted a couple years ago because there was not a 100% protection requirement. IIRC, it was something like 75-80%. Starting last year, it went to 100%.