Don't know if this would work, but maybe... fasten a cable to the header, threaded thru a pulley on the traveler,and back to the top of the door. That gives you 2 ft door travel for every 1 ft opener travel. Lots more than you need, so you have to move your stops way in. Also more load on the motor. Second cable to get the door down and seated:cable fastened to ceiling near motor, thru pulley on traveler,to pulley on ceiling, to pulley on header, to top of door( on an extension bar to give you seating leverage. Egad, on second thought, easier to move your air ducts. Oh well. An idea to play with.