I had a partial case head separation using a 1.8oz buffer

[Zeneffect]

So it's not really likely that the tear is going to outrun the pressure drop.

I agree fully with all of this except the above point. In my limited view, the tear must outrun the pressure drop to continually grow. if pressure has dropped below the tear (or continual tear) threshold, then it should stop. I think maybe its the way I have explained it that caused confusion and in reality we are in alignment in this regard.