Sorry for the confusion, in Blender itself, the vat preview is automatically generated- but at this time it runs from geometry nodes, not shader. When you create a new vat, a second object appears in scene myObject_vat. This IS reading the vat texture, just utilizing geometry nodes for vertex displacement in the same way a few engine would utilize a vertex shader (check out this automatically created geometry node group on the result '_vat' object for detailed notes and info)
My understanding is that since my last update of this tool, EEVEE now supports vertex displacement- so stay tuned and this will likely be an option in an update.
Very interesting addition. Thank you for your work! In one of the comments, the question was asked "Is it possible to make it support EEVEE or Cycles? I want to try it for crowd animation." You answered that this is done by default, but in my case no settings in the shader happened. Can you give more detailed information?