How do I export a 3D model of a PCB that shows the pads and the board cutouts?

When I try to export a .step or .x_t there are no visible copper pads or board cutouts. I selected "Export All" under "Copper Export Options" but it doesn't seem to make a difference. As a workaround, I am able to select "Export Copper Only" and export a separate x_t file with only the copper, and position that slightly above the PCB surface so it is visible. However, this is not ideal because traces are exposed. And it doesn't solve the issue that the board cutouts simply aren't there.

I'm trying to make an adapter PCB that will be a "component" in another PCB. So I would like to export a 3D model of the adaptor, and then place that 3D model into a component footprint. These 3D models are important because they will reassure me that I have pads lining up correctly. Also they will be important for the MCAD design.