Max99 is right about higher pressure preventing flats.
The good news is that most 11″ tires are tubeless which makes them much much less vulnerable to pinch flats, so you can play around with tire pressure a little more.
We usually run them at the mfg recommended pressures which tends to be 45 to 50 psi.
You’ll get a smoother ride at lower pressures, of course. You’ll probably also have slightly better braking and front wheel traction under hard acceleration as pressure goes down, until you get to about 40 psi. You’ll lose a little range at lower pressure, but not that much. We haven’t done a comprehensive study on that yet.