ATV Boomless nozzle sprayer

I have a Crop Care ATX40 sprayer with a boomless nozzle.  I calibrated my Kubota RTV500 as running 10mph full our in low-2wd.  At least if I have pedal to the metal, I know how fast I am going.  Nozzles set at 36".  Info sent with the nozzle kit says that is 4gpa at 30 psi which is a good pressure to run the 12 v pump at.  So, spraying rup or forefront.  with forefront, need 19-34 ou per ac product.  My question for those of you that have used this type of arrangement-with that low an application rate (4 gal per ac) am I better off doubling the water and spraying it twice or just put 20 ou in 4 gal and let her rip.  Spraying paddocks that are small.  thanks.rick

ATV Boomless nozzle sprayer