A way so we can drag foundations, walkways, stacakble conveyor belts, assemblers etc.
explanation: the player selects a starting point, clicks, drags the mouse, then the player will see the holograms of the "duplicates", then clicks and it will build as many buildings stacked horizontally / vertically as possible between starting point and endpoint
ps: i think it would also a good idea to define a "gap size" for example for splitters/ mergers so they will sit perfectly where they should be or to leave some walkable space between the buildings if the player wants to.