here’s a more practical example: model has 2 subd surfaces and a bunch of nurbs - export to obj with map-z-to-obj-y selected. Obj looks like this in other apps:
I’ll look at this tomorrow. We get the meshes in a different way for SubDs. For other objects we pass a transform to the mesher and the output is transformed appropriately. With SubDs, since you have the option of surface or control net, it does not go through the mesher. I probably forgot to apply the transform.