I went to a Cat scale and my payload is at 88.1%, front axle is at 89.5% and the rear axle at 93.2% of their respective ratings. The trailer was at 86.2% of max rating. I weighed the tongue and it was at 950 lbs. I always tow in tow mode. It tows great except for some buffeting when semis pass and a little porpoising over dips in the road .
Your tongue weight is high if your trailer isn't fully loaded. If your camper is at 86% of max GVWR, your tongue weight should be between 600 and 900 lbs, say 700 for a good target. This leaves a buffer for water or other items. Try moving any personal items in the front further back.
The manual calls for 50% front axle restoration, so half of the weight removed from the front axle should be returned when the WDH is connected. I.e. measuring from the fenderwell, if the front rises by 1“ when the camper is connected, it should go back down by .5" when the WDH is connected.
Once you get that sorted you can try some stiffer rubber with higher pressure. If there's a Discount Tire near you, see if they will let you try out some 20" inch wheels and D or E rubber for a few days. My biggest towing improvement came from going to 65 psi. It's higher than needed for my load, but the rear feels very planted. In contrast, the previous XL tires felt mushy and squirmed even at their max of 51 psi.