Adding rigidly secured mass at the top, to move the effective M of that mast further out, thereby increasing L could add capsize resistance from an inertia perspective, but you sure wouldn't want it there when the boat is heeled far over and it's pulling it down further. So you'd want to calculate how much this idea would affect the overall roll resistance of the boat (i.e. Is it worth it? Is it possible to add enough weight to make a difference?) and how would it affect the boat's recovery from a capsize/knockdown (i.e. Is it counterproductive?) There are probably more issues.
That was exactly what was thinking.
I seriously doubt that hoisting an anchor to the top of the mast in a storm will help prevent a capsize.
I was thinking in perhaps a very specific environment. Maybe in a wave-less anchorage that has a ferry going by every hour. Maybe a little weight aloft would dampen the periodic slop from the ferry.
Not sure it would but that was the type of scenario I was thinking of.