I have several opportunities where the prospect needs to save different features on different layers.  For example, a plate with holes is a single entity in a drawing.  We need to be able to put the holes on a layer that can be turned on and off.  Then upon saving to a DWG or DXF file, these layers would then need to be mapped to the appropriate DWG/DXF layer.

The same would be needed for parts in assembly drawings.  Customers need to have different parts on different layers in an assembly drawing.