There is a way to deal with the extra line, when I raced P-16s we used a piece of shock cord which we tied to the mainsheet approx 8-10 feet from the dead end and ran it through the gromett hole in the front of the tramp, under the tramp back to tramp lacing and tied it off. It kept that portion of the mainsheet on the tramp, which is normally the portion that if it slips over the back will pull the rest of the mainsheet over.