KiCad Multiboard: Cannot import PCB in VRML (WRL) in footprint editor

Hi,
I am doing a project consisting of several PCBs.
As KiCad does not offer multiboard support (project with two or more PCB with different technologies) I am doing each PCB in it’s own project. The connection between the PCBs are done by matching solder joints that are defined as footprints in a local fp-library.

In the footprint definiton for the solder joints on the main board that take up the other boards I have linked the 3D model to an exported STEP version of the board.

This allows me to see the complete assembly in the KiCad 3D-viewer and check for any collisions. Also the STEP-export of the main board contains the complete assembly which is really nice.

The KiCad 3D-Viewer gives me a nice rendering of the main board with all silkscreen artwork. But the PCBs imported as STEP (PCB-A / PCB-B) lack this detail.

I noticed that I can also export a PCB to VRML from PCBnew which gives me a *.WRL that can be imported by FreeCad and has the desired detail.

But when try to assign this *.WRL as 3D-Model for my footprint nothing is rendered.
Has anybody tried this before?

I am using KiCad 8.0.6, release build on Windows 10