Baking an Object Space Normal Map wIthout Projection Modifier

I can not bake an Object Space/World Space Normal map without using a projection modifier and a (highpoly) reference (It defaults to a tangent based NM). Tangent based maps can be baked without a projection.

There are two reasons why I want to generate an object space Normal map without a projection modifier:

[1] Use the rounded corners shader of Mental Ray on the lowpoly model and generate smooth edges without a highpoly model. I want to render an OSNM because these can be converted using tools like handplane to tangent space UE4 compatible maps.

[2] Render an object space normal map from a highpoly unwrapped model without a lowpoly model. These OSNM can be used to generate a tangent space normal map and a curvature map to create worn edges using substance Designer/Painter and Ddo.

When I set the normalspace to world it still renders as tangent when I don't use a projection modifier:

obj.INodeBakeProjProperties.normalspace = #world