There’s a reason I avoided four cylinder turbos for towing. Went with the Pro-4X and towed about 6,000lbs (car and trailer) about 150 miles and it was smooth, never stressed, and did better than I expected. Four cylinders and turbos will just get overworked.
You bought the wrong truck for towing. I know that trailer isnt huge, but it looks dense and heavy plus AT tires which add drag, plus its hotter then hell there. 55-65 mph is plenty fast for towing speeds not sure why you obsessed with needin2to go 70 everywhere towing.