My furler does not agitate when I tack. I just keep the furling line somewhat tight while sailing, and the line will not become slack. What actually jams up the furler drum when unfolding the sail is the line being fed into the lower part of the drum only,. The line comes in from deck level and then goes up to the drum. Then the line is not spread evenly along the drum height but fills up the lower part of the drum pretty rapidly