What's painfully obvious is that you don't know Jack about how a weight distribution hitch works. "Payload" is marketing. Means zero. Doesn't apply to the subject.
The limits are the axle/wheel/tire ratings.
Start as you should. A numerical baseline.
1). Take it to the CAT Scale at a truckstop. Empty of everything EXCEPT what's yours that never leaves the vehicle until you sell it.
2). Max fuel. Top off.
3). Get the reading. (Phone app if you want). The printed ticket comes up at the fuel desk inside.
4). Make a permanent note of the door sticker limits. Show the value remaining between the scale ticket and the limits. Both axles. What are they?
5). Whats the FF/RR WEIGHT BALANCE? Show as percentage.
Now, take it back with what you consider a reasonable load of cargo. Get another scale reading after tank top off.
Whats the percentage change on each axle from TARE to the present load? What's the percentage change to the gross?
No matter the weight added, it will nearly all be on the rear axle. That's by design.
So how is it you all miss that the device which cures the problem of trailer tongue weight is accurately known as a weight-distribution hitch?
The old pattern of distribution was known as the Rule of One Third. An 1100-lb tongue weight got spread over three axles, not just one. It'll be a little above 70% TW on the tie vehicle rear axle given that the crap pickup factory hitch receivers of today aren't anywhere near as effective in weight transfer as the custom ones we had built from factory-supplied schematics.
One aims to restore the Steer Axle weight value to what it was when solo. Three weighing same day. (Record cold overnight tire pressure).
Loaded for camping. Top off fuel. Max fresh water and propane. All passengers aboard each time.
1). Cross scale with hitch tensioned after a rough-in at home. (As much rearward hitch head tilt as possible). Trailer dead-level. In the bubble measured at doorway.
2). Cross scale again with only change being to remove all hitch tension.
3). Cross third time after dropping trailer.
For you noobs, the Steer Axle value in 1 & 3 needs to be the same. That's the starting point for dynamic testing.
Once accomplished, the next is tire pressure. Consult the manufacturer Load & Pressure Table to dial in exactly. Not over or under. Inside the vehicle manufacturer range (You NEVER use tire pressure to change handling or steering. You just screwed them and braking if you do). Trailer tires to the maximum on the sidewall.
The next couple of hours is on the road. The feel. As steering corrections are minimized. Pull off after this cruise-control steady state and check tire pressure rise. Should be no more than 7%.
Additional changes to hitch settings is in percentage forward to more than 100% of solo value. And then less. Get it right and it tracks on rails.
Next is brake testing. Given that bearing preset and brakes are properly adjusted (verify, never assume)
Your combined vehicle will now stop faster then the TV will when solo.
Test it. Full on from 65-mph to dead stop.
Fingertip steering and faster braking. If it doesn't, you screwed up. Just keep at it. The relationships become clear after only a short while.
The new guys with twenty years of RV trailer towing aren't your friend. Know nothing. Never had anything but a crap rig that wasn't even hitched right.
Haven't even a clue of what great design in the tow vehicle — hitch rigging — travel trailer are like. No basis of comparison with what's best and failed at hitching their own
"Best" NEVER includes pickups or box-shape trailers on leaf springs. Or drum brakes.
Steering, braking and handling are what count.
Test it.
I started more than fifty years ago. A schoolkid. Who'd have done a better job than any of you so-called adults. It's physics. Formulas. It's all predictable. Repeatable. Simple.
"Safety" is stability. Being able to remain lane-centered no matter what. Or take the emergency maneuver that won't roll the rig. Stop faster.
Any of you think my 21,000-lb Peterbilt is more stable than an 8,000-lb pickup? My 60,000-lb trailer more stable? (any type).
If you believe a pickup the best choice, prove it. In scale weighing (3) from above, you need to be near 50/50 weight balance for best performance. And that gear secured on or ahead of the rear axle so that, in a rollover, it doesn't move.
O, you'll have a rig that can't stop — nose-down trailer hopping on the front axle and continually wandering hooked to a truck with near empty bed. Inadequate weight distribution or steering apportion — and it'll be familiar as only the trailer front axle and truck front axle are doing the braking. Two axles. Not the four provided. Gee, I need a bigger truck!. No, it needed more weight to each axle.
Can't fix stupid. You choose. Right now, that's the shoe that fits. As it stands, I can do maneuvers with my 63' combined travel trailer rig that would roll a far lighter and shorter combination. Stop sooner. Better fuel mileage where the rest is the same. Less wear on tires and chassis. Etc.
There's nothing hard about any of it. Just some time. Maybe some tools. And, it goes faster and easier with a friend. His rig one weekend. Yours, another.
This is noob level. There's more. (Finesse).
Oh yeah. Andy Thomson is my age. Learned when I did. He and his Dad formularized what worked and didn't. Does SAE consider your expert friend a consultant to their work on this subject? Has your expert friend set up 12,000 combinations? CAN AM RV website is a great tool to leave the knuckle-draggers behind. See the article, "How to Set Your Torsion Bars", as the at-home rough-in before going to the scale.
.