My P226 has never had a pressure gauge on it,, only an idiot light.
I do not care if it is 5 or 50 psi,,, as long as the light does not come on when running,, I use it.
The P226 doesn't know it is doing anything while it is cranking the 72" mower deck even in 8" tall grass.
Maybe an idiot light would solve your concern??