You can put a tiller extension on any Wave, no matter when built. The difference is that on all of the original models, the mainsheet block system attaches to the clew of the sail BEHIND the tiller crossbar, so you don't have to flip the tiller extension around behind the mainsheet system when you tack or jibe -- you just bring the tiller extension across the boat with you, as you would with a Laser or most monohulls.

But with the new rudder system, the mainsheet system attaches IN FRONT OF the tiller crossbar, so you flip the tiller extension around behind the mainsheet system when you tack or jibe, just as with most beach cats.

There are pros and cons about both the old and new rudder system. I haven't had a chance to try the new rudder system yet, so I can't really give an informed opinion on that.

As far as the tiller extension, it does not affect those of us who race the Wave one-design, because a tiller extension is not allowed under class rules.

If you are souping the boat up for fun sailing or for open-class racing, and adding foresails and trapeze, and if you are sailing alone on the boat, I don't think it makes any difference whether the tiller crossbar and extension are behind or in front of the mainsheet system -- just a matter of technique in going across the boat. But if you have other people on the boat, it is more convenient for the tiller extension to be going around behind rather than across the deck, which is probably why most beach cats use that system.

Depending upon what rudder system you have, and how you are going to use the boat, there is definitely some room for creativity in terms of tiller extensions.