Materials of the new part system is node based and as such it cannot be fully exported to formats like OBJ or DAE. I try to export as much as I can but there are limitations. For example, OBJ doesn't support multiple uv layers so only the layer used by the colour map is exported. Meshes in the DAE files includes all layers but I could not find a way to specify which one is used.
Besides, there aren't anymore bump or metal maps as such. You can find the public section of the specification here
Only the Blender Advanced Add-on fully support all features.