About Poser scaling:

At first I also thought that animateable joint parameters would be a great help to create realistic proportions for adults and children.

But in the end the "new" Poser scaling is flexible enough to create the shapes I want to create and I hardly ever tweak the joint centers anymore.

Figure on the left is V3. The rest are "Davids". All are just morphed and scaled, no joint center editing except the girl in the bikini which was made years ago, so she is "custom rigged" the old fashioned way.