IMO instant spawn of buildings won't be nice...
As 4 myself I'd like 2 see building in few steps...
Delivering of materials (refined on base or bought)...
Placing foundation and materials on building site...
Some welding, connecting and installing of concrete (or other) panels...
Installing doors, windows, airlocks, connecting 2 power sources and installing cameras + other kind of sensors...
And then installing inner equipment depending on type of room/building...
My point is - instant spawn of few tons of materials instantly composed into building is not nice 4 realistic simulator...
I know it was similar way in MCC1 (building sites for room required in next mission)...
But in 2nd MCC I'd like 2 personally or with robotized help build some structures and components and devices...
Have I mentioned a variety of grades/quality of created stuff depending on skill and minigame success?..