Billy Goat
WKR
The straight on videos look like there is less oscillation with the right fletch. I think @Billy Goat brought up here or a different thread about wanting the flex thing to control rather than go with the flow. Maybe there's something to that.
I got no idea.
But if the point of fletching is drag, I don't know why it should be on the path of least resistance.
I'm solidly in the camp of it doesn't matter which direction tho.