Alex,

I followed with great interest your airflow tests on pattern planes. Brilliant idea to use those new micro cameras and tufts, and send the plane through the classic manoeuvres.
As I read about the knife edge situation, and the discussion to attach some "fences" along the sides of the fuselage it came to my mind that I bought about 15 years ago an old, used and well worn pattern plane fuselage for very little money. Once it was shipped to me, during unpacking I recognized it had just such fences integrated to the fuse sides. I forgot about that until few days ago!
Obviously, some other guy had the same idea as it is discussed here. I still have no idea what was the name of that plane, nor do I know who was the designer and if there has been any report if those fences worked well.

I will post some pics later tonight.

Hope to read more here from your very intersting investigation!

Dominik