hello,
I knew of a software which made a transfer between v-ray sketchup and v-ray max properties, just that I miss its name at this point. It was a script for 3ds max which imported material properties such as glossiness factors and bumpiness slots...
Though it can't be FULLY compatible since 3ds max is a different modeling platform than sketchup and will never be completely compatible with, also v-ray for sketchup is totally different than 3ds max one.
And if you know your parameters you can apply them in v-ray for max too . I know you don't like working twice on something, but that's the best way sometimes.
LE - here it is :