WMA motorsports has a 1000 lb capacity platform made for one large road bike. It has a 16" platform close to the hitchmount, and a 6" motorcycle slot out farther. That 16" is roomy, and I have a 12" class III extension to make it even more roomy. I could easily put a second dirt bike aiming in the opposite direction there. It is steel, and would be easy to add some heavy duty
Here is there description $400 right now):
1000 LB MOTORCYCLE DIRT BIKE E-BIKE TOW HITCH CARRIER RACK HAULER + GAS CAN CARGO SHELF STORAGE
Once the bike(s) are unloaded, the rack can serve as a front porch for your camper if you have a back door.