Safely towing a 27ft tt with nissan frontier crew cab

I saw that the rvision 23rbs is rated 4500 lbs dry and 6100 gvw. I would estimate loaded with gear you would be about 5500 lbs, not 4000. The tongue weight is going to be over the 610 lb rating and bring you within 300-400 lbs. of your payload capacity. With a full tank of gas and two passengers, you'll be beyond the payload capacity.