So what you're saying is......a 1" helical would do the same thing.....because "it's still helical"?.................
I'm questioning if it does any good (negligible).
Of course I have to lab to test this but....
A 2" blazer was designed to control an arrow at least as well as a 4" vane so in theory a blazer fletched helically(sp) will work equally as well as a 4" helically fletched vane and possible better depending on what type of material the 4" vane is made of and how well that vane stays rigid in the "wind".
Of course it may very well be negligible but looking at the pics I posted I can't see how the straight vanes would create nearly the amount of spin or drag as the helical vanes.