Kevin,

The best parameter to compare a normal boat and one with less weigth in the extremities is the moment of inertia (around each axis).

Equal boats or masts have the same weight, the same moments of inertia and the same "stiffness". It is simpler then using radius of gyration as a parameter, which only confuses things.

If I understood correctly, the idea is to have a one design mast in order to reduce its price and the work done to tune the rigging. The downside is that it will create an optimum crew weight in the Tornado (for each wind force) and the sails will be more complicated to customize for each crew.

Cheers,