"Contrary twist" is the independent movement of the tub/tray to the body of the vehicle. This is designed to reduce the amount of shock through the body of the vehicle and improve the ride quality when the tub/tray is heavily loaded.
Because of this, it is not recommended to mount the same item on or across both the body of the vehicle and a canopy/tub rack. Please note, when attaching awnings, long platforms, rooftop tents, ladder racks, or any similar product, you must only attach/secure it to either the roof rack on the body of the vehicle OR the rack on the tub/tray.
The same rule applies to carrying long loads such as kayaks, ladders, and SUP. Items like this can be tricky to secure properly so please be mindful and take care when doing so.
Mounting or securing an item to both the tub/tray and the body of the vehicle will result in added strain and stress through the item. This will likely lead to the item being damaged or it may cause it to fall off the vehicle completely.