Just a quick suggestion.
Currently i find myself using the Q build menu a lot, which is a fantastic tool. However, a lot of my building is simply copying what i have next to it (I.E flooring/smelters etc).
I had an idea, we use the middle mouse for nothing currently (or i don't at least) could that be made into a "copy" button that selects the schematic of the building you are looking to quick build or "copy"?
It would make expansion a heck of a lot easier without having to constantly change my hot-bar!
let me know what you think,
Amateur Factory Builder