Wow, that is a pretty hefty-looking tiller! Seems like overkill for such a little boat that has very neutral helm.

One comment:
An advantage of the new rudder system with the tillers higher and back farther is that the helmsperson can also get back farther (back UNDERNEATH the tiller) on a reach, and therefore go faster and keep the bows up. Your extension will effectively be a bar that prevents you from doing that.