[MrBasse]

I'm looking at that as a view straight down your wheels on one side with the wheel in the center and black bars as the axle.

If that is the case that lip would be outside your perimeter and wouldn't be legal in my view according to the rules. That wouldn't fit as a minor protrusion either. The only way to make that work is if that bend sticks out less than a 1/4" from the vertical plate or if you add supports every 8" for your bumpers.

What is stopping you from flipping that over so it goes in towards the robot like the kit chassis does rather than out? That would retain the strength you gain, would negate any issues of being legal, and make you bumper situation considerably easier to figure out.