It would be nice if a float that matched the current avatar scale was exposed to avatar animators. Being able to adjust things on the fly based on the current scale would be wonderful.
EG: Head proportion. When I make a taller version of my avatar I usually bump the head scale down to 90% to make it feel proportional.
Some constraints with offsets will also break when scaled and this could be alleviated by letting us manual adjustment them based on the current scale.