Just FYI to future readers: I took it a step further because I wanted to duplicate a group at each vertex rather than an object. To do this I created a separate blender scene containing my tree (generated with Gen3) and I put all the objects making up the tree into a group. Then in my real scene file I Appened in the tree group, added a new instance of it and duplicated the “empty” object according to waylow’s instructions. (Perhaps there’s an easier way but that seemed to work).