Gary Friesen had this all worked out for his Catalina crossings. A special and longer metal fitting for hooking the sail. Reefing points in the sail, new downhaul fitting and hey presto. All this is possibly available in the archives of the beachcats maillist?

Gary also prototyped and sold a special "walk the plank" righting device.

If we are going to sail upwind with a reefed mainail, the shape will be less than optimal due to the changed luff curve.