Been shooting 4 fletch for 25 plus years.
I use 4 - 5 5/16 feathers, I prefer natural bars. I also want as much helical as I can get, and still keep the quill flat on the shaft. LW-RW makes no difference, as long as all the feathers are the same wing, on the same shaft.
I also use tapered shafts.
My shots on game are generally very close, I prefer those 10 yards, and under.
I want my arrow to recover from the archers paradox as quickly as possible, so the arrow enters the animal as straight as possible.
I find that with my arrow-combo, I get just that.
I know I lose speed, and cast, but at 10 yards, who cares.
I do know, if I shoot one of my 4 fletch arrows, and a 3 fletch arrow with the same size feather, that I will gain better than 50 yards of distance in a flight shoot.
So unless your shooting for distance, it really doesn't matter, how much speed-cast you lose.
Noise, from the arrow has not been a factor for me in hunting.
For years, when stump shooting, I've fired arrows very close to my dogs, they never flinch till the arrow hits. Thats through 4 different chessies.
It's the movement thats gonna get you in hunting, not how fast, or how quiet your arrow is. Your arrow is never going to be faster than the speed of sound!
One thing on noise that I've noticed, is if I burn my fletch higher than 11/16 on the shaft, I will get more noise. The reason this happens is that you are out of the oil line, and the fletch will become ratty, this leads to more noise.
Whew
Jim