View3D with importScene in separate window can't display embedded 2D items

If you have a View3D with embedded 2D items in one window, and want to show the same scene using importScene in another window, the 2D items do not render there. The follwing warning can be seen in output:

[26060] Scene with embedded 2D content can only be rendered in one window.

This issue makes it annoying to edit 3D scenes with embedded 2D items in QDS, as the 2D items do not show up in 3D view.

The attached example reproduces the issue.