Inserting Point for Collection of Nodes

if I drag more than one node from the palette to the diagram they are not top left align on the mouse pointer. Instead of this the mouse pointer is centered to the collection.
How can I make the top left corner of the collection hanging on my mouse pointer?

I’m not sure there’s an easy way to do that.

Looking at the source code, it seems that you might be able to override DraggingTool.AcceptData and explicitly shift the node data. So you could override this method to call the base method and then modify the data in the return value. This assumes that there is location information in each node data object in your model.

Hmmm, upon further reading, I don’t think this will work. The private code in DraggingTool always shifts all of the new nodes relative to the mouse point.

Ok, than - maybe I can live with that.
But I have another problem, then. The code is not including my Width and Height properties on the NodeData. So it calculates the center from the collection without including the Bounds of the Nodes.
What can I do to help the code getting the bounds of my nodes?