The way I see it, they are trying to improve strength and stability at the pole end. The luff loads on the kites is quite high and there can be a quite a bit of movement up and down at the end of pole. Easily demonstrated by lifting a boat on the beach by its spinnaker pole. A F16/F18 would have 5 to 10cms of movement quite easily. So by minimising this movement then it could give them that extra x% needed. It is an Olympic year and Booth/Lovell both tried exotic sail material in the lead up to Athens. And with it potentially being the last time for a multihull gold to be offer, trying these kind of things could be difference.