RealityKit Instanced Rendering on visionOS

For more context here is a minimal RealityKit view to reproduce the test setup.

    var body: some View {
        RealityView { content in
            let material = SimpleMaterial(color: .systemPink, isMetallic: false)
            let mesh = MeshResource.generateSphere(radius: 1)
            
            // MeshResource.generateSphere creates a model with this name
            let model0 = mesh.contents.instances["MeshModel-0"]
            let modelName = model0!.model
            
            // This implementation tries to create a new MeshResource vs MeshResource.replace()
            var instances: [MeshResource.Instance] = []
            let instanceCount = 20
            for i in 1...instanceCount {
                let translation: SIMD3<Float> = [Float.random(in: 0...1),
                                                 Float.random(in: 0...1),
                                                 Float.random(in: 0...1)]
                // Nothing in the docuementation indicates what the id needs to be.
                let instance = MeshResource.Instance(
                    id: "MeshModel-\(i)",
                    model: modelName,
                    at: Transform(
                        scale: [0.05, 0.05, 0.05],
                        translation: translation).matrix)
                instances.append(instance)
            }
            var contents = MeshResource.Contents()
            contents.models = mesh.contents.models
            contents.instances = MeshInstanceCollection(instances)
            do {
                let finalMesh = try await MeshResource(from: contents)
                var spheres = ModelEntity(mesh: finalMesh, materials: [material])
                content.add(spheres)
            } catch {
                print("failed to create mesh resource \(error.localizedDescription)")
            }
            
        }
    }

Here is a screenshot of the RealityKit trace.

Maybe there is some specific requirements on a usdz file that will trigger RealityKit to used instanced rendering.