How to update UniqueValueRenderer with new symbols

[ironmaskito]

Hello all, I am wondering if it's possible to update UniqueValueRenderer after it has been initialized with symbols and their corresponding fieldNames. My application creates a GeoJSONLayer, which is assigned a UniqueValueRenderer that contains all the symbol information for the displayed geoFeatures. However, I'd like to update some of the symbols for the rendered geoFeatures if a user hovers over it or selects it.

The only case where I have been able to update a symbol within the geojson layer is when the UniqueValueRenderer already contains the fieldName, symbol pair. Is it possible to add a new symbol to the UniqueValueRenderer and refresh it so that a specific geoFeature's symbol gets updated? I've tried reassigning the renderer property of GeoJSONLayer after modifying the UVR, but the symbol that's supposed to change style just disappears.

  private updateFeatures(results, layer: GeoJSONLayer)
  {
    if (results.length >  0)
    {
      const updatedGraphics = {
        updateFeatures: []
      }

      results.forEach((feature) => {

        feature.attributes[UNIQUE_VALUE_RENDERER_FIELD] = "drawing"; // set new style
        updatedGraphics.updateFeatures.push(feature); // update geojson feature
      })

      let symbol = {
        type: "simple-marker",  // autocasts as new SimpleMarkerSymbol()
        style: "square",
        color: "blue",
        size: "8px",  // pixels
        outline: {  // autocasts as new SimpleLineSymbol()
          color: [ 255, 255, 0 ],
          width: 3  // points
        }
      };

      const renderer = layer.renderer as UniqueValueRenderer;
      renderer.addUniqueValueInfo("drawing", symbol); // assign new symbol to new style

      if (updatedGraphics.updateFeatures.length > 0){
        this.applyEditsToGeoJSON(updatedGraphics, layer); // apply changes to feature
      }

    }
  }

  private applyEditsToGeoJSON(params, layer: GeoJSONLayer)
  {
    layer.applyEdits(params)
      .then((result) => {
        result.updateFeatureResults.forEach((updatedFeature) => {
          console.log('feature with id ' + updatedFeature.objectId + ' updated');
        })
      })
  }