[gsxrken]

Yep.
When I purchased my adjustable WUR from Brian Leask, he advised I go with “the heavy duty diaphragm option” if I intended to boost beyond stock levels.
If your friend is on a road trip, you should try to find someone with one in stock that they can overnight to him where he’s stuck. Leask’s turnaround time, and the tuning you’d need to do with it, don’t lend themselves to a roadside swap scenario.
Call Brian (the poster just above this one) to check stock. Good luck.