Tommy,
Can you elaborate on why you say the Coleman propane does not work as well?? From my experience with MANY engine brands, Propane works just as well as propane/butane mix BUT, some adjustments usually need to be made to the ECU for start performance to match. The ONLY reason why Powermax became the brand of choice for some manufacturers is because of the pressure level of propane/butane mix which is a bit lower than straight propane. Years ago, when onboard start tanks where introduced, some modelers experienced propane line ruptures. Typically, these ruptures where in high temp conditions where, when baking in the sun fuse temps can exceed 150 deg. This raises the propane pressure in the tank while also softening the propane tubing.
Today, I find many customers removing onboard tanks and going back to straight propane for startup. The propane is easier to find not to mention cheaper, valve is cheaper and it eliminates carrying propane on board.... Heck, harbor freight sells an adapter so you can fill a coleman bottle directly from you barbecue tank!
Todd

PS...trigger valve is now sold!