...does not effect loading or rendering times in VMP or Adobe Atmosphere-does it?

Don't quite understand the question!

In VET you can change the scale of the model via x y or z in thr mtx file.
If you import an mtx file that is a size of x,y,z=.3, .3, .4 into atmosphere will it be significantly faster to render than another model of size xyz=1,1,1 even if the 2 VET models have the same content (but a differently scaled size factor?)

I am little bit confused on this conversations . Is the scalling really affects the rendering speed of the atmosphere. If so tell me the ways to improve it.