Opv volumetric shot help - duo steel

Hi everyone!

I have an ascaso duo steel and I am loving it! Shots are great. But now that I have dialed in my shot i would like to have it programmed.

My issue is that when I pull my shot the opv always goes off to maintain pressure. When I then use the programmed shot I get variable results e.g. 38 g out programmed, and output can vary from 34-43g.

I always end up using the scale and checking to stop or top up as needed. Not ideal

I don't see a way to grind course enough for pressure to build but opv not to go off AND still get good "espresso"

I have tried with the opv at factory setting of about 11 and tried dialing down.

Any advice to get the program output more reliable?

Thanks in advance for your contributions:)