Maximum pressure is determined by the tightness of the oil pressure bypass spring.
If it is a 60 psi spring setting, then all the oil volume that creates pressure will bypass when the valve opens therefore limiting the pressure to that chosen 60 psi.
If your situation is showing an actual amount of 85 (or whatever) that is obviously LESS than the amount needed to open the pressure bypass valve.
Needless to say, hotter thinner oil will not create as much pressure per rpm.
IMO you definitely have a high pressure pump.
I prefer backing the spring down to 60-65 psi maximum.