I have judged many boxes with burnt ends and not once did I ever note if they were the same size or not. Like chicken, the "mirror imagine rule" is a myth that too many teams believe in and I don't think most judges ever clue into. But just one more thing that someone who probably teaches classes has to add to the class presentation so folks think they are getting some inside info when paying big bucks for a class.
I think the 270 team (husband and wife) seem to make their living mostly by selling to comp teams. They are on the road constantly, and do many comps. I think he devised this mainly for nailing down the timing of cooking. If they are the same size, they will cook more evenly and at roughly the same pace.
I don't know the guy at all, but he seems to have a little mad scientist in him. To my knowledge they don't do classes, but they are trying to sell them and their smokers. So yes, I see your point as to the sales motives, but I also think he is just trying to invent useful products for a very small niche that may find them beneficial or are looking for that very narrow edge in a comp.
I'm not someone who necessarily looks through 24 thighs to find the six that look exactly the same, but obviously there are a lot of people who do. I think this product is made for those types. I personally just thought it was kind of a neat little gadget that I would most likely never purchase.