GVWR is paper number. It has everything to do with registration fees, but very loose correlation to vehicle actual capacities.
Having 12-foot campers COG is my main issue.
Having Supercab for small dogs, all heavy stuff, like water, tools go on Supercab floor.
Takes me some talking with DW to move all heavy liquor from rear compartment into front compartments.
Still per couple of drives via scales, my COG is behind rear axle and as mentioned, 200 lb of waste water in rear tank can badly affect the ride.