stomp pad

I am an avid 3d printing enthusiast and I just started printing with TPU (flexible stuff). I just ordered a Garage Rocker and figured it would be an awesome idea to print my own stomp pad. This is what I came up with. It isn't the best quality print and I can probably adjust temps to make it...

I realize that stomp pads aren't technically bindings, but this seemed like the closest category. Here's my question: I've always seen stomp pads stuck somewhere between the bindings, usually right in front of the back binding. Why can't or why shouldn't it be mounted just BEHIND the back...