Blow n Go,
Looks like i was totally wrong, not the first time , maybe the last...but i doubt it. Meant no disrespect to you just have never heard anything like you said before. I do want to learn, that one reason i visit this forum.
3DFanatic's example is a perfect demonstration of changing yaw stablility and the result. At 30 degrees of elevator throw the airflow was not that bad over the rudder and the plane was steady. At 50 degrees, you are blocking a considerable portion of the vertical stab with a big board (the elevator), disrupting the airflow, so the configuration becomes unstable in yaw. The result - wing rock.
I have one plane that does just as you and 3DFanatic describes (rocks bad with 50 degrees elevator throw not bad with 30degrees)with what you are saying would a bigger rudder help?