I saw that too. In theory it's an advantage. In practice it get's in the way of the rudders and they can be fraigle.

I had a system that attached to the rudder pin and extended the hull to about 25% of the rudder width on my 14. It seemed to work very well in light air and one side fell off in heay air. It seem to reduce turbulance at the stern but it was not worth fixing because at that time I made bigger gains learning the boat.