On big monohulls, you are on a pretty short tether, that is running on a jackline fore and aft, so you can't really fall very far -- just be hanging off the side of the boat.
Doesn't really relate to small boats.

That's why I liked the idea of, on small boats and cats, having the tether fastened forward so you can't end up dragging behind the boat.

And I don't agree that you can't get any sailboat, monohull or multihull, to round up and stop really fast, no matter what sails you have up.