Left wing seems to work better for this anchor. The cock feather needs to be at about 9:00, and there isn't much leeway up or down to position the back correctly against your nose. Be careful that you are touching the BACK of the cock feather with your nose, as it feels like you're doing that when you're really touching the side of the feather, and of course that won't work for establishing a consistent draw length. I find that shield cut gives me a better indication that my nose is in the right place than parabolic feathers.
Because of the position required, left wing gives better clearance on the shelf side. I find with left wing feathers, the quill on the inside hen feather will slip nicely into the corner between the rest and the strike plate. This is the main reason for using left wing feathers.
Because of the forward mounting of the feathers, I find it difficult to use feathers longer than about 4 7/8". Otherwise, the feather sticks out of the end of my fletching jig. Also, the feather reaches almost to the shelf when the arrow is nocked, which is particularly a problem with longbows that have a low brace height. Fortunately, my feather chopper is adjustable so I can cut slightly less than a 5" feather. I would be interested to know if you're able to solve this problem with 5 1/2 inch feathers.