Fuel pump pressure relief valve , progressive or on/off

[hediki12]

Hey im just wondering on how the prv works? I know inline pumps dont have them, and the gss431 chokes at 80+/- psi .were as the walbro gss391 (inline 255) doesnt and maintains higher flow from around 55psi up. This lead me to believing that the prv system that people modify in double pumpers to get more flow is progressive. The more pressure applied the more it vents till it reaches full tilt and shuts off. Bosch 044 and wally 391 have a very linear flow compared to in-tank set ups . Im asking this because im planning on modifying 2 aero 340 but the valve activates at 95-100psi which i wont past those fuel pressures. Thanks in advance