Boom sprayer newbie questions

So as you may or may not know I have a 30ft boom sprayer that I completely rebuilt and I finally had a chance to use it but I have a few questions about the operation... according to the tag I got with the nozzles it says 4 miles an hour at 20 psi gives you 21 gallons in acre, which is about what I need for libertylink beans. But my field is way too bumpy to go 4 miles an hour. The booms are bouncing all over the place and I feel something may break. Not only that but 20 psi doesn't come out very well but 30 at 5mph works well but is way to fast... So my question is 1. Can I spray more gallons per acre and go slower and good coverage? 2.5 to 3 miles an hour gives you a nice ride. And 2. is it advisable to add a couple of pounds of weight Midway across the booms to keep them from bouncing? I'm all new to this and am trying to learn. I was told 36 Oz to the acre of the chemical. 30 to 40 psi seems to give the best pattern. Can someone help me to get a understanding of how this works?

Boom sprayer newbie questions