I recently upgraded to Rhino7 and hence also upgraded the exporter rh7 -> Composer.
Unfortunately, I now encounter a heap of problems with the materials - this partly might be Rhino related, not sure about that.
First and foremost - a lot of textures are not exported correct. I reported this already with Rhino5, however it obviously has not been fixed:
Second, a wrong ambient color sometimes is used for the imported material, as you can see above
Third - the material names are not imported anymore, instead, a custom name (Material-xyz) is used:
thanks
Cyana