The Whites Pee valve creates a real problem. I have a solution, but it requires some engineering beyond my capacity.
I bought a Fusion years ago, just after it was invented. It did not have a Pee valve. When I decided to add one, I bought a Salvo valve, which is exactly what Whites now uses. I had them install it, abut they put in a hole in the inner bag that was much larger than it needed to be. The big problem with the Fusion is that you have to seal the inner bag and the outer skin together with pressure from the outside of the two skins. In my case, all it took was a little tension on the inner bag when putting it on to pull the oversized hole out of center enough to create a leak.
To cut to the chase, the Whites dealer I use now for repairs (DRIS) will not set up the seal that way. They instead create a firm seal on the inner bag that will not leak. They out a hole in the skin, but they are not connected. When you need to pee, you have to reach down, feed the outer valve through the hole in the skin, and then pee. That is a PITA. Using my old Salvo valve, I could make a perfect setup if I could seal to the inner bag, feed the stem through the hole in the skin, and then put a washer and nut in place that would keep it there so that I could pee whenever I wanted without having to manipulate the opening with my fingers in the pee stream. Unfortunately, the valve stem is 1/8 of an inch too short, and I can't do it. It seems to me that Whites could make a pee valve specifically for the Fusion that would incorporate that design. However, even though I have tried to sell that idea, it has not gone over well and has no hope.
I generally take a leak before buttoning the suit up and that solves the problem. 
