It is odd that the maker would setup the TT with less than 10% tongue weight unless they were expecting the added items to make up the difference.
Dealer/sticker tongue weight is based on dry weight. Dry weight is as shipped, empty propane tanks, no battery.
WDH moves, by lever action, weight to the tow vehicle (TV) front wheels and some to the TT axle(s). Mine moved 220# forward and 80# rearward with my previous TV. I was a bit overweight for some specs and did a radical cargo review and removal. Haven’t reweighed since.