I have an exact copy of CPLR's on my Enigma, there is something to it as it completely removed the pitch mixing I had in knife edge even with extreme amounts of rudder. It also significantly increased the effectivness of the rudder especially in level flight. I am down around 15 degrees of deflection for everything but snaps/spins, about 50% of that is required for sustained knife edge flight. I was running around 20 degrees for a similar feel prior to adding the wing.

So in my opinion it certainly has an effect.....the question I am still resolving is if the changes caused by the appendage is truly benefitial or not. The plane flew great before and it flies great now