I apologize if I'm overstating the obvious but, don't forget to allow for the dense center core of the patterns. When you center a bird with even a SK or IC choke the target will be smoke, even at 30 yards. I know how hard it is to allow for centering a bird in a pattern as opposed to fringing it, because we can't center them all the time, with any gun. But ....... with some guns it just seems easier to do that, and with those guns it seems like we can get by with less constriction.
Unless we're having a bad day. Then all "rules" are out the window!
