Yeah anytime you mix big cams and single plane manifolds a 50cc shot on the primary is almost manditory as with some squirter changes. Now putting one on the secoundaries can be a preference or a tuning aide, like I stated before I prefer a leaner carb set-up and thats why on that particular set-up I didnt go square on the pumps not to mention I was running a nine inch slick where traction was marginal at best and I didnt want to take the chance of braking the tires loose.
A double shot off the line just might make you go from a lean stumble to a rich stumble, so make little changes one at a time seeing what works and what doesnt, keeping waht works and removing what doesnt.
And dont make the mistake of trying to cover up something that doesnt work by changing something else, theres a happy medium to everything and finding it is the key to tuning correctly, again to your particular set-up.
Goodluck, Charles