If I were you, I wouldn't bother about the tacking. When you sail at sea, there is not need for. I cannot tack on my cat also and I don't really miss it.

Looking at your video, I would like to express my admiration for what you have achieved so far. In the past I've done my share with trying to build minicats and mini sailingboats (larks).
So ,I'm one of the few guys who really know how difficult it is to compress all the basic forces of a sailing cat into 10 feet. Moreover sailing with it on waves is only possible when you have invented a stable and balanced design considering the presence of the extra demands the waves are posing.

So, respect.