Had some time to test the plugin. Didn't go too well. This is what happened:
Exported all content as obj's from Cinema4d, imported them in Modo, created materials and linked them to the MXM-files created using C4D. Exported a few times to Studio as I proceeded linking materials, and that worked fine. Then I created two new materials inside Modo, saved them to the folder with the other mxm-files. Subsequently Modo crashed every time I tried to export to studio.
After this I couldn't even export the old C4D scene to studio either. So now I'm rebuilding the scene in C4D
Here's my spec: Windows 7 64, Modo 601SP2, no plugins besides GOZ + Modo.