Recommended Tongue Load Limits Exceeding GVWR when Including Payload?

I'm too tired to verify your numbers but I'll try to simplify it.

Your Passport curb weight is 4224#, the max amount its suspension/ tires/ axles / brakes can support on the road is 5291#. The weight of people, and their cargo, will subtract from that difference. Don't forget your fuel tank, full is heavier than empty.

It all quickly adds up, leaving very little allowance for the tongue weight of a trailer (as a minimum allow 10% of its total loaded weight).

Hondas' are marketed as mighty vehicles - but the truth is (regardless of a tranny cooler - another weight robbing accessory NOT included in your original curb number) they're very poor for towing.

So now the question comes down to how much over are you going to load it? How far will you tow it? How fast will you push it?

I wouldn't hesitate to pull an additional (several) hundreds of pounds, at slow / prudent speeds - for a few in-town miles, but do consider you Don't have stronger brakes so longer stopping distances will be required.

Me. I'd never do this on the freeways.

Lets once again try to keep it simple. The max allowable payload (which are the passengers, suitcases, pets, PLUS installed accessories like tranny cooler, tow hitch and safety chains.) are limited within that 948 pounds.

Just like adding more people - adding weight to the tongue would directly affect your payload. However so long as it all totals below that 948 pounds you're good to go - your chassis suspension, axles, tires can handle that.

Reverse logic, if your tongue weight is at the max (500 pounds) then you can only have 448 pounds of people and stuff. Conversely less tongue weight means you can add more people and luggage (beer coolers / tools) - but it is still limited to that 948 pounds.

A second concern: Any more than 500 pounds on the tongue may result in hitch failure / separation. Not good.

BUT WAIT, there's more to be considered. From the other side of things, whatever your trailer (RV, enclosed hauler) weighs, to control sway while traveling it MUST have at least 10% of its weight on the tongue. So a 5000 pound trailer properly loaded should have a tongue weight of 500 pounds (and more weight better fights sway).

But with that load you'd have a rolling weight (both loaded car and trailer) of maybe 10K pounds. I believe that exceeds Honda specs - but I'm not gonna try and chase it down / from memory I'm thinking its about 9000#. Obviously a 4K trailer improves things, 3K is even better.

Now eventually a balance is made where the Honda can safely stop the load - and when properly balanced control sway when a semi passes by.

AND ... there is more. Get an actual road scale weight to double check as the trailer manufactures have a tendency to also overlook things (like the weight of propane cylinders, 12V batteries, spare tires). Don't forget a Brake controller and harness, checking all tire pressures, etc.