I never intend to take my 12' camper for off-roading, but I was taking it on forest roads, where truck gauge reported 18% grade. My biggest dilemma was camper ties holding it from sliding back, but it hold just fine.
Don't expect anybody to tell you side roll specification. I did some research years ago when I bought sophisticated suv, who was rated for taking 100% grades, but no word about side tilt.
It is liability issue as static tilt and dynamic tilt are 2 different things and nobody will give you a number.
But fact is, that as you noticed, TC being tall unit, is bottom heavy and even 3000 lb of camper is not much comparing to 8000 lb of truck.
Meaning your COG will be just few inches above truck bed floor.
Make sure to reinforce cabinet locks