I'm taking down a couple trees that need to be climbed and brought down in pieces because of being too close to a building. I'm using a split tail tie in with a Blake's hitch and a pulley tender. The issue I'm having is after being loaded the Blake's hitch is staying too tight after being unloaded for the pulley to slide it up the rope. I've been using a 5/3. Is there anything I can do to help the knot not cinch up so tight so that when unloaded the pulley can slide it easier?