Right now the SDK seems to only worry about polygon limit, which I learned is not that big of a performance hit in VRChat. Things like combining textures and meshes in blender actually help more.
We should reward avatars that seek out these optimization technique's
We could have some sort of optimization score per avatar that determines the amount of polygons that can be used, for example:
If you have only 1 mesh and 1 material your polygon limit will increase to 40-50k
if you have 2 mesh and 1 material you get 30-40k polygons.. etc, etc..
(Dynamic bones could also be taken into consideration with this equation, counting total child bones for example)
Right now there is no incentive for people to use optimization other then being nice :)