knap 123,
I use tail feathers on a lot of my hunting arrows (they are really quiet) I fletch at about 2 to 5 degrees offset (not helical). Since I cut my fletch between 5 and 6 inches long I only get 1 feather per half, so if you use the rearward most part of the tail feather you can use both sides of a tail feather in an offset jig. After I split @ tail feather I group them into rights and lefts so I use all the same on the same arrow....but as far as fit goes either side will work in an off-set jig.
One other thing about tail feathers is they go past a bow handle without even a hickup let alone any deflection. They are "softer" than primaries of course but for quietness they just can't be beat.
half eye