[Duncan Macdonald]

Did you actually put it on a scale to verify the weight savings? I would be surprised if there was a significant savings by using a material ~45% as dense and twice as thick.

The frame as configured does not pass bumper rules and needs additional thickness in the corners. It does just squeeze into the size limit but how do you expect an inspector to measure 0.005 or 0.020 with a tape measure that probably measures in 16ths? Do you lose that much usable space by making the frame a quarter inch narrower? I promise it will get you through inspection faster.

Do you have your manipulator mounting planned? One of the nicest features of the kit frame is that there is a mounting point every inch.

It took a long time for one of my teams to learn that just because you have resources available doesn't mean it is smart to use them.