Depends on what the Flu-Flu’s are being used for. They are slower, louder and very restrictive flight distant.
I am like Patrick, I use left wing helical. However, for a right handed shooter right wing helical with cock feather in works just as well. (I shoot cock feather in with left helical anyway. So the differences is really moot). Anyway, I prefer left helical, and I mount to the shaft with a straight clamp using a 1 degree offset. That is all.
Increased overall mass of feathers used will reduce speed and increase noise.
The main purpose of Fletch is to stabilize the flight of the arrow as it comes out of paradox.