The sail condition as mentioed above is (imho) huge. my buddy put new halsey canvas on and it erased it. then I promptly preformed an accidental gybe (with no time for ye ole 'gybe ho') while no one was knocked in the head or mob who know how much of a load i dropped on his brand new canvas!!
I dont see how it could be desireable as you are just adding drag via rudder.