[aerohead]

Originally Posted by freebeard

I like trolley tops. www.pinterest.com/reneperret/trolley-top-trailers/

In extremis, they would act as a rooftop fence to kill lift when the trailer goes sidways.

I agree that they could spoil lift, if sideways, however, they'd simultaneously increase roll moment ahead of the yaw moment, making things potentially 'tippy' in a crosswind gust.
There are videos of overturning RVs online. It's pretty terrifying.
I think that center of pressure issues can be resolved without adding leverage arms to the roof.