Lowering weight (< 150 kg/320lbs) and reducing drag would be good.

However, strongly reducing tendency to pitch-pole would be the biggest improvement. That would enable us to push much harder.
And it would draw many more people to cats. A lot of people are reluctant to sail cats for fear of cartwheels.

So I think T-foil rudders (that may be tilted up for beaching) and flatter bottoms (as on the Infusion) - both mesasures to reduce pitching - are important developments.

(And, if someone could find a way to reduce the space taken up in the boat park, all arguments against cats would be eliminated. Almost.)

Stein