Similar line of enquiry to this thread: Allow StaticMeshEditor to change the source mesh Pivot - Feedback for Unreal Engine team - Unreal Engine Forums
It would be great if when exporting fbx meshes from the editor, it actually exported the smoothing groups too. Currently it’s not possible to import meshes into the editor, then seamlessly export them back into your 3D package (particularly 3DS Max) - because information is irreversibly lost.