The Sculpt algo also has a wah and that one can be mapped to the expression pedal. I believe the filter-pre and/or filter-post parameter of Sclupt can be mapped “backward” (the toe is a low value and the heel is a higher value) to do what you want. I believe you can turn down the low-drive and high-drive parameters to reduce/remove fuzz if you want a clean wah. Good luck.
