I've used cock feather in with a standard RW three fletch since I was a kid while shooting longbows and self bows. If I have a bare shaft coming off the string, around the plate, and over the shelf of my longbow clean and straight, adding RW feathers cock-in will clear equally well. But, If I add RW feathers cock-out, the bottom hen will bump the corner of the shelf plate and effect flight. I must slightly raise my nocking point to allow extra clearance for the hen feather with RW cock-out. Therefore, cock-in with the lower nocking point gives me cleaner flight.
As to the high speed videos, every single one that has been posted here and on *********** shows the RW cock-out hen feather striking the corner of the shelf plate when using full size hunting fletching. You may clear with tiny fletching, but I think it is impossible for hunting fletching to clear the corner cock-out with a tuned low nocking point.
later,
DB