OK I don't have the switch yet but did have a 10k resistor and 1/4" jack. I wired with resistor between tip and ring. When I touch the two leads together closed I get 0 ohms and have min range set 0% modulation, when I untouch the two leads I get 10k ohms and have max range set to 50% modulation. So SPST will work and of course SPDT will too.
So first off let me say thanks to Mr. X for the idea to begin with.
Although I am still messing with settings (like rise) to get that true rise and fall that VB-2 gives. I don't really notice much difference in the rise settings through the whole sweep of the knob. The other problem is when 0 ohms is present there is no fall it is just off.
Anyways, thanks guys and whoever sends me the switch first wins :)
I'll let you know how it goes when totally completed.