Though Blender 2.80 is not yet production, the exporter is being updated to support more PBR features, so going to version 6.1.
Going to update for BJS 4.0, so to use these new features, 4.0 is required. Adding Clear coat, sheen, & anisotropy. See this topic for more. Not going to try to support anisotropy as a texture, at this time, or anisotropy direction. These features can only be supported using Principled Shader for now. Here is the new mapping:
The other feature is generic environment textures from @PatrickRyan (thanks), are now going to be included in the zip file, and can be selected instead of using the world node background node.
Probably out before end of week. Needed to actually do a map picture for myself, so posting this now. If something seems wrong, say so.