I have to agree with Rex. You just need to get used to the volume of spray you're using. Just get moving and spread it out faster. I say coat the fiber and let the stuff do it's thing. You can't really put down too much prespray unless you're going through more than 1 gallong per 100 ft. Just my opinion.
Most multi's came with a #4, my mytee has a 2 #6's. They are correct in telling you to go faster on lay down of spray for productivity, but, you can also put in the smaller sized tip if you want to go slower and have less chances of spraying the walls and base boards. Helen pushes me to fast as it is.