If pumping is dynamic, remove pumping feedback if it is wrong
After messing around with the pumping quite a bit I have come to the conclusion that whether or not I get a (clean) pump according to the scoring system has absolutely no correlation to how much height I get. If I try to pump with timing that seems correct according to physics, I will get massive height on a quarterpipe despite missing the pump feedback entirely and getting no rumble + nothing on the score (not even unclean).
My assumption is that the pumping in skate. is entirely driven by physics and the speed gained is a legitimate consequence of the change in your center of gravity, which means the feedback is entirely fake, a "guess" from the gameplay code that frequently guesses wrong. It looks like the feedback wants you to stand up during the curve, but the times you actually want to stand up are 1. after you exit the curve going up, and 2. right after landing on the upper part of the quarterpipe when coming down. If you do this you will get SIGNIFICANTLY more speed than trying to hit the timing that gives you a (clean).
If this is the case, you need to remove the pump feedback. Nothing on score, no rumble until you can find a way to make the feedback match the actual gain in speed. I promise you that if I'm right about this that 99% of the confusion is from people being fooled by the feedback, which can tell you you're pumping perfectly when you're actually doing it so suboptimally that you're losing speed.