This is what Robbie told me when I was on the Viper, at the time it seemed like it wasn't enough until I did it, and that is that end of the tiller arm shouldn't go out past the edge of the hull. The time turning is longer, but you stay moving, and don't have to accelerate as much to get back up to speed.
Also smoothness on the tiller is super important. Every time you turn the rudders you are slamming on the brakes. Pin the tiller extension against the hull when not tacking and use both hands, (one on the extension, one on the crossbar) when flopping the stick over to the new side. Robbie had us tacking the boat with the rudders up, which I had know clue was even possible.
edit- I'd be surprised if anyone, except a very few elite, would have a mirrored image of your illistration for both directions of a tack or gybe. We're naturaly prone to doing things differently with one side of our bodies than the other.
Got to add smoothness with steering is key. Recently i have jumped on a foiling moth so only have centerboard and rudder in the water, so being smooth is extremely critical. Any movement in the rudder bleeds off speed immediately. Something like 10% straight away, more if movement is severe. So going back onto the A-Cat i was amazed how much quicker I was just because my steering had improved and that was all down to being smoother.
