Funkymonkey
Reading your last post I think you might possibly have missed the point of the nose weight limit. It’s not the structural integrity of the tow bar, it’s the balance of the car.
The weight pushing down through the towbar is behind the rear axle. It’s therefore acting as a lever around that point and changing the weight distribution of the car. If it’s too heavy on nose weight this makes the front end of the car go light and affects steering and braking (all cars) and traction (front wheel and four wheel drive).
You have to be extra careful with bike racks and towbar nose weight limits because the weight is applied over a distance that extends out from the tow ball location. So the effective limit is lower due to the leverage.
You risk prosecution and invalidating insurance by breaking that nose limit.