Scanline - Mental Ray Work Flow?

[RevitGary]

I am trying to develop a work flow between Scanline and Mental Ray. Not having much luck. My objective is to put my Revit model in to Max and Scanline render on a daily basis. I use the fbx export from Revit and link into a max scene.

 

I apply my standard materials and standard lights in my "scanline scene"

Next I want to xref objects of that scene into another scene / file. Then apply Menatl Ray materials and lighting for overnight high res images. I need to keep both Scanline and Mental Ray scenes identicle in modeling thats why the "xref objects"

 

My poroiblem is i cant get the Mental Ray file set up when I try to "xref objects" it locks up. Any ideas? I am using max 2009