Thanks for the discouragement!  (ya, that's not something you hear everyday)  It got me to give up on my previously fruitless path to look for yet another.  Since Poser has problems matching the joints on scaled conforming figures, I tried to reduce the problem by hacking the shoe figures off at the shins.  The shoe figures without thigh bones didn't have that problem anyway, so that fixed the bending issue in the shins here as well. 

However, there still was a problem with the feet.  Seeing that the shin scaling was specifically causing the problem here (setting the tracking to "bounding boxes" can be useful), I moved the shoe shin scaling to the shoe BODY and rescaled the feet and toes to match.  The solution I ended up with is a bit of a hack, and it'll still require redistributing cr2 files for the shoes, but at least it works.

Now, I just have to fix some of the morphs and it should be good to go soon!