I had a front hitch on the old truck and have installed one on the new truck. My trailer is smaller than yours, but I carried a Honda Jazz on the old truck. The Jazz is only 50CC and weighs about 150lbs. I had no problems with overheating or airflow.
I wouldn't put my 250 cc Honda Reflex on the front, because it would block the headlights and being that much larger may impede airflow.
The other problem would be my rack pivots in the middle to facilitate loading the scooter and the centre of gravity with the bigger bike is on the wrong side of the pivot.:S Makes it real hard to load. Now I want to get a scooter in between the two and rather than a test ride ,I want to do a test load on the carrier.:D
Good luck in your search.
Oh and as someone else said, be careful with the extra 2 feet out front, it makes it sooooooooooooo much fun backing into a tight campsite!
Brian