I borrowed a good idea from a friend. The pole sits in a PVC tube (pretty standard, I reckon), the flag at the top is flaked onto the pole and a fabric sleeve is pulled down over it. The end of the sleeve has a light piece of
line connected to the backstay.
I've seen so many boats with a faded tattered flag fluttering off the top of the MOB pole, this solution keeps the flag in good shape and deploys it automatically, the sleeve stays behind still tied to the backstay.
I now use this on my own boat.