Wanted to ask, if it's too low, is it too hard to push or causes back pain/imbalances etc?
i dont have prowler, but ive got this big ass tyre that i though of fitting it with a "platform" in side to hold the weights to push ala prowler. Thing is, it's kinda low, roughly midpoint between the floor and my knee height. So since your problem is regarding height, i thought i'd be able to relate.
btw TS, good luck on building your prowler. I wish i could also.