I help a friend install one on a 42S. I was at first skeptical installing a staysail on a in mast main, but B sail all was good. They liked the idea of using the
windlass bulkhead to fasten the chain plate. We removed the
winch, installed the plate and added longer bolts with little modification. You'll need a rigger to install topside of the
furler fitting, just above the spreaders. Needs to be drilled and tapped, but B says okay. I'd give them a call to make sure your specific model and supplied equipment will allow this modification without changing the mast or something drastic.