We first decided to leave this feature out of our implementation, since the renderWindow interaction is VTK based. But as long as only the world position is used in the event it should work. For setting points in 3D it actually works even with zooming and moving the 3D visualization.
I've provided a fix for this in personal/schroedt/interaction-in-3D.
An attribute for the mapperSlotID was added to the config of the interaction file and is loaded and set in mitkInteractionTestHelper.