This has been probably been covered, but if not, here it goes.
Modelling/part creation in IC for render outside IC has some problems. If you render a metal part, then it's easy, but with wood it's a different story.
I wanted to render a stool in plywood, and converting nurms-based models to mesh for uv mapping it's hard. I found to ways -
1. export in 3ds - and by faces - not materials. Try to keep the parts together in keyshot when moving the around. In this way I could assign one material to the edge face and one to the top.
2. select the part - export to .sat - the import it back in and you get the brep. Then select the faces until you get to smartpaint them. The smartpainting makes it easier in keyshot, as you just have to swap those colors with materials.
I'm new to IC, so maybe there are better workarounds, but this works for me for now. Obviously, complicated parts with many faces can be a pain to smartpaint.
two plywood materials added on the render below. one for the edge, and one for the flat parts. (The idea of the stool is a friends)