Direct3D support cannot be installed in VBox Additions 6.1.8

The Direct3D option is not available in the VBox Additions setup 6.1.8

• Configure Virtual Box machine to have 3D support enabled
• Install ReactOS RC image (tested with 0.4.13 and 0.4.14 RC24) with default settings and complete graphical setup
• Boot in safe mode
• Install VBox Additions for the corresponding VBox version.

Virtual Box 5.2.26 (and known lower versions): The extensions setup offers to install the Direct3D support (if we are in "safe mode")
Virtual Box 6.1.8: There are code page issues in the German installer and the option for Direct3D support is always greyed out. As a result, 3D applications such as Google Earth cannot be used in ROS on this virtual machine.
Left: Virtual Box 5.2.26, Right: Virtual Box 6.1.8

As this is seemingly independent of the ROS version I guess it is not a regression on ReactOS side, but either a regression or changed support on the VirtualBox side. I wonder if it is possible to have ReactOS work around this issue.

I have not yet tested any other VBox 6.x version.