The PRV is not a regulator, it is a pressure limiting device in this particular case. The engine does not need to strictly regulate the pressure.
The oil pump must have enough capacity to press the oil through the pipes at idle RPM to lubricate all the places. That's the low limit.
At high RPM the pumped volume will cause pressure to be still below the top of green arc, if the oil has normal viscosity. That means at RPM on top of green the pressure will be in green (always was in my engine). If the oil is cold, the resistance in pipes is high, pressure would rise to the top of green arc and that's the point where the limiting device the PRV will kick in and cut of the excess volume to keep the pressure at the set value. Until this moment it is completely closed. Technically it is a D-type regulator (D=derivating, other types are P=proportional and I=integrating).
If during the normal operation let's say 2350 RPM and warm engine the oil pressure was at ca. 60 psi before and now it is 90 psi, that is a signal something is wrong. It can be the gauge. Or it can be that the resistance in system is too high - something is blocked - some parts of the engine are not properly lubricated.
I will check the gauges. It is a G1000, wish me good luck.
If the gauge is OK, the problem is bigger. Did you hear in the past about blocked pipes?