[tongzilla]

Would that not give an open clubface at separation, assuming that separation occurs prior to low point (which is what I have been assuming - possibly erroneously)?

Like I said in my previous post, I was referring to the ideal application (2-C-1). Therefore Separation happens occurs at Low Point, and we get a perfectly straight shot.

Also, for a hitter seeking to offset the slice tendency of angled hinging, wouldn't the clubface need to be closed (to the Left Arm Flying Wedge) for the longer clubs?

Yes. But a detailed discussion would require going off topic...maybe someone else can help (?)