So you're saying it's impossible for a completely sedentary guy with a 20" SVJ to jump <30" if bodyfat doesn't decrease much?
Does the same hold true for a VJ with any number of approach steps?
I don't want to get into a silly argument but I want to be clear exactly what you mean and if I can find some convincing case studies to post up perhaps you will change your mind that strictly no one can increase their SVJ/VJ by more than 20% without losing a lot of weight