Not saying it is not the truck..but at this point, based on specs and towing a fifth for three years, I'm moving that concern a little further down the list. After TW, as loaded for travel, I still have about 500+ lbs payload left. In several respects, the specs beat many lower end 3/4's. It still may be "not quite". If there's nothing that can be tuned on the hitch itself, I'll move on to tire pressure. TW with this trailer will be almost impossible to change much, unless I carry gold bars in the front.
As noted earlier, the 3P has taken care of a significant amount of the issues. Just looking to get it that last bit that may or may not be possible.