I had an issue this week with a project that I have encountered a few times. I am hoping there might be a feature to help with this. I started a new SketchUp project, but I was copying bits and pieces from several other projects (all were VRay at some point, and some were as old as 6-7 years old). When I went to render, it took an unusually long time creating the light cache and rendering. I sent a render to cook when I left the office and when I returned the next morning it was only 60% complete. I knew there was a boogieman somewhere.
I made a component of all of the new Cosmos assets I had placed and saved them out because I didn’t want to lose all of that work, and then I used the utility to wipe all VRay data. I reimported those component groups and went through the process of reconfiguring my model materials. This worked, and it rendered as expected.
Now, my request would be a feature that keeps the Cosmos assets and rebuilds all materials as new VRaymtl materials, copying maps and settings from older vray materials that might be in the model. Any missing maps or issues should pop up in a dialog so the user can address them.