Can I export from the 3D model to a 2D section view also the shadows…?
That’s not possible right now.
In the meantime you can use the section with shadows in whatever display style you like, ScreenCaptureToFile, bring that in as a PictureFrame and lay it under the 2d section view. Its not the most ideal method but it works. The drawback is the image is a raster and does not automatically update. However, it works well for a presentation rather than a working drawing.