What gear were the bikes in @ 40mph. Roll on could be first or 2nd?
Did first and second gear runs with same results. From first mine would pull the front end and carry about a 6 inch power wheelie up to about 75 or so before going into second at redline, his being lowered 3 inches, he was able to keep the front end down. It didn't matter though as we still held neck and neck through both gears so in my mind that eliminates shifting technique as there was no loss or gain going from first to second.
I've convinced myself it is most likely a combination of weight difference and 3rd gear mapping.