What happens once the masthead buoyancy inflates and you manage to right your boat? Does the extra windage make another capsize (in strong winds) more likely, or do you discard it? It seems to me once it has been used you are a bit exposed in the event of another capsize if you have discarded the inflated buoyancy.
I ask because I capsized well out in a Scottish sea loch a couple of years ago and after the inversion and righting I would not have wanted extra windage at the top of the mast. I fitted an in-sail pocket as it seems to offer less intrusion and better multi capsize capability. I have yet to test it though, having also fitted extra reefing lines, but I am always interested in the best options.
When we went over the inversion was very rapid (wayfarer world with aluminium mast), giving no time to reach a grab bag or anything. As a result I keep essentials (flares, radio, phone, whistle etc) in a waistcoat over my bouyancy aid. Thus if I am in the water I have it all with me and there is little interference with normal sailing; indeed it means that the radio is always to hand and not at the other end of the boat when you need it.