Say you're designing the rig. You select a wire cable that will take the calculated load plus a safety factor of, say 3x that.
You make sure that whatever that wire is connected to (chainplate?) is stronger than the wire by another factor . . say 2.
Then, whatever that is attached to . . . perhaps in the case of a headstay chainplate, you design with yet another layer of safety.
The object of the exercise is to ensure that the last thing that will possibly break is the hull.
I think it would be prudent to design anchor roller arrangements in a similar way . . . so they remain intact after the chain has broken, and don't rip the bow off the boat.
Of course, building all this stuff this strong costs money. Which could make "yachting" undemocratically expensive . . .