I have been using a truck camper and a 27' RV for awhile and twice the water lines inside blew out due to me forgetting to use the pressure regulator. It may never happen to you, but is it worth taking a chance. Get an adjustable pressure regulator and always use it when connected to shore water pressure, even at home.
I have always used a regulator. I was in a park one time and the motorhome next to had a water leak on one of their sinks water line that he could not stop by tightening. I loaned him a spare regulator I had and the leak stopped.