I carry a Kymco Agility 50 scooter on an aluminum Harbor Freight hitch rack behind my 24' E450 chassis Class C, for local transportation when needed. The scooter weighs 210 lbs and the rack about 50 lbs. There is not one bit of difference in the handling or steering with that load on my small house E450. No perceptible added squat on the rear scooter on vs. off. That comes with having 4500lbs of NCC.
That said, I would not carry any more than that 260 lbs of dead cantilevered weight on my unit, and certainly wouldn't do double that on an E350 with only 138" wheelbase and proportionally more rear overhang.
