I have towed for many years at maximum tow limits for cars and trucks.
It sounds correct to say that the nose weight should be considered as load to the tow car, but in practice, vosa see it otherwise.
I used to drive a VW LT35 curtainside truck and tow a 2000Kg trailer behind it. It was like a red flag to a bull as far as interplod were concerned. first port of call on the weekly spot check (yep got stopped that frequent) was to see if I had a tachograph, which I did. Then came the game of "you need anoperators license too", but I didn't as the trailer weighed less than 1000Kgs unladen (thats legislation). By then they got so rattled that anything is fair game, so weight is the next wrangle.
Vosa weight truck & trailer (car & caravan) together to check Gross Train Weight.
Then they weigh the trailer uncoupled from the truck to get the trailers Gross Weight.
Then they weigh the truck solo and also they check each axle weight too.
Finally you hook the trailer up, then they place scales under the jockey wheel and get you to uncouple again. That way they get the nose weight of the trailer which in the case of a goods trailer is set at 7% max of the gross weight. But also it must not exceed the towbar loading defined by the manufacturer.
Basically the same jazz goes on for caravans, therefore, discounting any weight transfer to the tow car.
So unless you play by their rules you won't win their game.