Hello, I've probably encountered a performance issue with the Layer List widget in api version 4.16+ (version 4.15 and below is fine). After a research, I came to the conclusion that the render method of the widget is called too often, so there is a drastic slowdown of the view (lagging, long rendering time, almost 1000ms). In the Layer List sample on your site everything works fine. I use 10 or more widgets and about 10 layers in the map application, can it be related to that?