I am seeing some weird rendering shading problems on .obj files exported that might be due to having named positions attached in Rhino.
It seems rhino is also exporting the verts or something inside the named position when exporting a file in obj format. As if Rhino is attaching the file with the extra named position geometry.
I have to look at this more but it just crossed my mind as some problems in the obj export are occurring for me. I don’t have an example to post as the file is nda and large. Maybe you can try with any model with named position and I’ll try to cook up a postable example.