Walking on the roof is OK, PROVIDED THAT YOU DO NOT, walk forward of the first main bow or rearward of the last main bow. IF YOU DO, YOU WILL DAMAGE THE SEGMENTS. The main bows connect the front and rear shells the the body.Many years ago, Airstream had a photo of a 30 foot trailer, with 30 employees on the roof.
It's like anything else, be reasonable, and use soft shoes.
"IF THE ROOF IS WET OR DAMP, DON'T GO THERE. YOU MAY BE VERY SORRY IF YOU DO AS IT WILL BE VERY SLIPPERY." GUARANTEED.