The idea is useful as it provides an out-of-the-box experience to help streamline the editing experience within an application. The plug-in installed user only need to "click and drag" the mouse similar to what's already implemented but more advanced. The initial "click and drag" [manually] over the existing location of a structure will generate "footprint" and highlighted the footprint, left mouse click opens up option window for custom height/random height extrusion process. InfraWorks is amazing to me at the moment and feels the potential possibilities to improve functionalities is at the fingertips Autodesk coders. The screenshot should help you guys see my point.
Regards,
Ahmad M.