That is original design although new component, and the same type of quicklink was used by the boat builder with the steel backstays. I assume the SWL is about 1/3 the breaking load, so that puts it about 17,000 pounds which is stronger than the original dyform wire. Yes it could be the weak link now. Not sure, but it's proved "strong enough". My rigger told me the "normal" SWL for steel is 1/3 breaking, and for rope it's 1/5 breaking.