Forgot to mention something about the pressure switch.
They work on a "Cut In" and "Cut Out" system with a set difference of about 20 psi.
So if you turn the screw towards the + and increase the "Cut Out" pressure, you are by default also increasing the "Cut In" pressure equal to the amount you raised the "Cut Out" pressure.
A gauge costs nothing and I have no idea why nobody installs them.
If the pump, by default, "Cuts In" at 30 psi, and "Cuts Out" at 50 psi - when you turn the screw towards the + and increase the "Cut Out" to 55 psi, it will by default increase the "Cut In" pressure to 35 psi as well.