ImageryLayer performance with external service

EricDurbin

I'm using an imageryLayer with an external service in 4.21. There is a slight delay upon initial load, pan, and zoom within the map while it is calling exportImage and is processing on the server side. Is there anything I can do to improve the performance or perceived performance upon the initial or subsequent requests?

let mosaicRule = new MosaicRule({
lockRasterIds: this.objectId,
    method: "lock-raster"
});

let rasterFunction = new RasterFunction({
functionName: "Natural Color with DRA",
    pixelType: "U8"
});

let layer = new ImageryLayer({
id: "rgbImageryLayer",
 url: this.serviceUrl,
 mosaicRule: mosaicRule,
 noData: 0,
 renderingRule: rasterFunction,
 format: "jpgpng" 
});

map.layers.add(layer, 0);

https://landsat2.arcgis.com/arcgis/rest/services/Landsat8_Views/ImageServer/exportImage?f=image&bbox=-10489816.173983572%2C5392062.728110802%2C-10441431.53507912%2C5411401.2962669255&bboxSR=3857&imageSR=3857&size=1266%2C506&format=jpgpng&noData=0&mosaicRule=%7B%22ascending%22%3Atrue%2C%22lockRasterIds%22%3A%5B3150200%5D%2C%22mosaicMethod%22%3A%22esriMosaicLockRaster%22%7D&renderingRule=%7B%22rasterFunction%22%3A%22Natural%20Color%20with%20DRA%22%7D