Yes, you absolutely can do this.
The Supertruss is very popular.
For a lighter trailer a simple 18 inch 2 inch tube extension would work, but your trailer is pretty heavy.
I would just get the Supertruss, or if you want more info then look at the Truck Camper Forum on this site. Truck campers weigh about 1,000-3,000 lbs, and like a cart, sit in the truck bed past the down tailgate and towing often requires extensions. There is all your knowledge and experience.
I had a TC and towed a light cargo trailer so the 2 inch extension worked fine for 80,000 miles with no / zero issues or concerns.