Weight over a strap, cable, or chain absolutely will slow it down in the event of a break. Attempting to accelerate even a small amount of mass bleeds off energy rapidly. Depends on the weight of the chain/strap/cable vs the weight being used to how effective it is.
There are better methods than tied off to the ball hitch, but the ball is pretty strong. A shackle with a grade 8 pin or bolt is better.
