a CDI furler (which I highly recommend) after many years of hauling these things around we have settled on carrying our furler extrusion on deck just inside the stanchions this entails a nice gentle curve and prevents any radical set (which can happen, especially in a black tube in the Arizona/Mexico sun - which is still ok for short periods of time, I just wouldn't want to leave it in storage like that for any period of time.) Ordinarily an extrusion is the approx length of the boat (given the gentle curvature) and does not stick out much on either end. This method has worked well for us towing two to six thousand miles a year. When at home I keep the extrusion in a white pvc pipe fastened to the top rail of a chain link fence which is always in the shade in summer. This keeps it quite straight.

In the photo you can see just the end of the extrusion showing at the bow sprit.