It is possible to add multiple Physical Materials per a Material slot to a single mesh.

I have a cube with 4 material index slots. Each material on the mesh has a different Physical Material set up with it. They all work by themselves. I do not have a Physical Material applied to the collision of the cube. It seems the various Physical Materials aren’t working. My research has suggested that its only the Physical Materials applied in Index 0 but I wanted to confirm this. Anybody know for sure?