Originally Posted by ChiefGreedyOfficer
Does some weight on tougue add to the overall cap? It should.
When you say "cap" I am assuming you mean payload. If that is correct, the answer is no.
The GVWR of the trailer is the lowest weight rating of the "critical component" used to build the trailer and has nothing to do with TW; just total weight regardless of where carried or supported (wheels or tongue).
While it is remotely possible on your camper for the selected tires or the axle "to be that component", it is FAR more likely to be the frame; followed by wall construction and wall "openings".
Overloaded frames flex at every road bump causing frame cracks and cracks at the corners of the laminated side wall panel penetrations (slides, windows, and doors).
Higher GVWR rated campers not only have heavier axles and tires, but have heavier duty frames and contain more aluminum tubing in the "studding" and boxing of the laminated walls and ceilings.
Just upgrading your axles and tires will do nothing to change the payload available. If you need more, you need a different camper.
As to weight distribution hitches and the transferred weight, GVWR is determined with the WD hitch in its "unloaded" configuration (all camper wheels plus tongue weight). You must also weight again with the WD connected JUST TO MAKE SURE the axle and tire ratings are not exceeded with the redistributed tongue load.
If your camper is below its GVWR with the bars/chains unhooked, and exceeds the weight rating with enough WD to make your truck level, you have the wrong truck trying to carry that camper's tongue load.