MaterialX materials are not instanced about blenderusdhydraaddon HOT 4 OPEN

#usda 1.0
(
    defaultPrim = "Geom"
    metersPerUnit = 1
    upAxis = "Y"
)

def Scope "Geom"
{
    def Xform "node1"
    {
        def Mesh "mesh"
        {
            def Material "someMaterial"
            {
                token outputs:surface.connect = </Geom/node1/mesh/someMaterial/node.outputs:surface>

                def Shader "node"
                {
                    uniform token info:id = "UsdPreviewSurface"
                    float3 inputs:diffuseColor = (1.0, 0.0, 0.0)
                    token outputs:surface
                }
            }

            int[] faceVertexCounts = [3, 3]
            int[] faceVertexIndices = [1, 0, 3, 1, 3, 2]
            normal3f[] normals = [(0, 0, 1), (0, 0, 1), (0, 0, 1), (0, 0, 1)] (interpolation = "vertex")
            point3f[] points = [(0.5, -0.5, 0), (-0.5, -0.5, 0), (-0.5, 0.5, 0), (0.5, 0.5, 0)]
            uniform token subdivisionScheme = "none"

            rel material:binding:preview = </Geom/node1/mesh/someMaterial>
        }
    }

    def Xform "node2"
    {
        def Mesh "mesh"
        {
            over "someMaterial" (
                references = </Geom/node1/mesh/someMaterial>
            )
            {
            }

            int[] faceVertexCounts = [3, 3]
            int[] faceVertexIndices = [1, 0, 3, 1, 3, 2]
            normal3f[] normals = [(0, 0, 1), (0, 0, 1), (0, 0, 1), (0, 0, 1)] (interpolation = "vertex")
            point3f[] points = [(0.5, -0.5, 1), (-0.5, -0.5, 1), (-0.5, 0.5, 1), (0.5, 0.5, 1)]
            uniform token subdivisionScheme = "none"

            rel material:binding:preview = </Geom/node2/mesh/someMaterial>
        }
    }
}