RadMap is actually powered by Kendo Map
. Binding of shapes (and bubble layer also) is a matter that is entirely controlled by the Kendo Map widget.
Possible, built-in data optimization or interaction performance options are not available. Basically, everything that is bound is rendered, and panning or zooming re-renders the entire layer. If such optimization are implemented in the map's engine, performance issues on the client might be encountered.
Due to that, it is recommended data optimization to be done manually by filtering data or affecting the precision of the shapes fetched by the GeoJSON data-source.
For example, in this demo—http://demos.telerik.com/aspnet-ajax/map/examples/data-binding/client-side-data-binding/defaultcs.aspx
—we had the same problems. Due to that, as you can see, the data-source is filtered based on user's decision (changing continents via the dropdown). Also, the precision of the shapes is reduced, i.e., the geographic are cut in half in order to reduce the amount of the loaded data. With bubble layer, precision is not an option, although some sort of filtering should be a valid option to improve the performance. Although, such a filtering should be implemented by the application developer based on the precise application requirements.
If, however, you think this is a point of improvment for Kendo Map, you can put your suggestion in Kendo's User Voice portal, so to be voted for (http://kendoui-feedback.telerik.com/forums/127393-telerik-kendo-ui-feedback