I use the same sprayer shilh 450 on my vines. I use the 1.8 setting , walk briskly and ue 3.75 gal. For 88 vines. This works well for me. Hope this helps.
My sister in law had marquette trained to vsp, she indicated a harvest of 5 lb. Mine are trained to twc and I harvest around 15 lbs. I really didn't think she took good care of her vines so that could explain some of the differences.
Received the report from UW Madison, test showed no disease that would cause dieback, only collestotrichum, which is a fruit rot. Indicated that it may be cold related. However we had a relatively mild winter.
Thanks for the update and good luck. I have stink bugs in my house and they stink. Can't imagine what they taste like in wine. Hope all works out well.