Thats exactly right, most painters set the gun inlet adjustment
to wide open.
Also: The pressure measured at the gun useing a gage
is measured with the gun spraying wide open (trigger
And unless you have oversized fittings and air hose, you need to
run high pressure to the gun's gage to compensate for the CFM losses
due to the std fittings, like 70 psi., then regulate down.
HVLP's take a lot of CFM, that's important for it to spray its best.