From Dodger: "It's a proportion ratio thing. Impossible to keep all the joints perfect through the growth. I kept it as minimal as was possible. Problem is really that Vicky's thighs are disproportionally and unnaturally long. For Anna, who is proportionally correct, to grow into her, the thigh/shin length ratio shifts which slightly offsets the location of the knee joint. It's also intended to create a 'halfway down' younger morph injection for V3 and M3 and that's in the works. It will be a freebie to any purchasers of the appropriate figures. At that point the morph will never practically be needed at over .5."