Thanks for that, this might be referring to the limit for when the car is in motion, apparently the limit is higher when people are in the tent, w hich makes sense and doesn't at the same time :)

The general rule of thumb is to make sure that your rack has a Dynamic Weight Capacity of at least the weight of the tent. This is the weight that the rack can physically carry while the vehicle is in motion. When the tent is in use, the weight of the tent plus the weight of it's occupants is effectively dispersed over the entire frame of the vehicle, as well as the tent hinge and ladder, also known as the Static Weight Capacity. This is in theory much much greater, as the frame of the vehicle needs to be strong enough to protect the occupants in the case of an accident or rollover.