My biggest fear, hence the urgency, was whether the 3x2 upgrade could be moved to a place that a 4x3 could not occupy.
I can move the graphics of buildings to overlap with other buildings (doing so does trigger a message about how buildings cannot overlap), and by moving the graphics I can move the graphics of other buildings into the seemingly vacated spot (again a message about how buildings cannot overlap appears). But none of this has any affect on the physical locations of the buildings. Buildings whose graphics have been moved one square away from the road still function as if they were connected by road. It appears the 3x2 dimensions for the copper dragon seem only to apply to the movement of graphics rather than the movement of the building itself. Generally the message about how buildings cannot overlap should not appear, a red box around the building usually appears and clicking the location you wish to move it does nothing, but when the dimensions for the graphics do not match the physical dimensions then the green box around the building is maintained allowing you to move the graphics separate from moving the building.
As far as it seems, this is not exploitable. What is being played with is not the true location of the building, and reloading the game will reset the graphics to their true location.