Quote - I thought I'd read that one should use collar Twist, rather than shoulder Swing, in order to avoid unsightly creases in the upper arm region.  If I try to pull the arms back, however, using the Twist rather than the Swing, the upper part of the shoulder, at the back, collapses.  This isn't as pronounced with Swing in use.  So I'm wondering if there is a posing "rule" for area.

Maybe I just misunderstood the rule about avoiding Bend + Swing > 90? 

No, that's a good point actually, and precisely why I was looking for testers. (@lesbentley: basically, see if you can find any poses that you'd expect to look decent in a well-rigged figure, but that don't. If you don't have much time, just going through the ones you remember had problems in the past will help, too. I'm hopelessly unorganized and just keep forgetting stuff.)

I've noticed earlier that pulling the arms back is a bit problematic, but forgot about that. I'll have to see if there's a good way to get that pose as is, or otherwise revise some of the JCMs in that area.

-- I'm not mad at you, just Westphalian.