Would it be possible to get the skin morph modifier in Max to react to the z-rotation of the bone by wiring the z-rotation parameter to a new bone's x or y. Then using that value to drive the skin morph. I've been thinking about this and have yet to test this idea.
You would have a redundent looking bone wiggling about somewhere, maybe set up a set of these away from the object and hide them?
Has anybody tried this method and would it actually work?