"customizable_texture" for Home import object, created in 3DS Max

Anyone any ideas how to create an object with a "customizable surface" material applied in 3DS Max? 

This material allows one to create an monitor screen for example onto which your PC desktop can be broadcasted. 

See :  https://support.oculus.com/326598838066496/ instructions.

In 3DSMax, I added "customizable_texture" to the name of to the used material, and then exported to GLB using the Babylon plugin.

After I imported it into Oculus Home, the object has the option to be broadcasted to, but when I select that option, nothing happens

I also tried to exporrt as GLTF, open it as a TXT file and added the "customizable surface" to the material name, and then converted to GLB.

Same things happened.  .

Then I created an object in Blender and added the "customizable surface" to the material name, and export to GLB
That gives an import error without further detail, and although it keeps showing the red exclamation points / boundary box after import, it does actually allow me to broadcast my desktop onto it successfully.

Any ideas how t make this work, ideally in Max?