Add custom control to Subgurim Maps

Is it possible to add a custom control to the GMap control in the Subgurim 开发者_如何学运维library?

I see that I can add a GControl with the GMap.AddControl method. I tried to create a custom GControl by implementing a WebControl inheriting from IGControl. Although this compiled and executed nothing was rendered on the map.

No, it's not possible. The AddControl method adds specific googlemaps API controls.