When blueprinting if you ghost a quality building but only have regular building in your inventory drones will take your common building and place it in the quality building, upgrading it to quality.
Example:
1. Ghost place a Rare quality flamethrower
2. Only have common flamethrowers in inventory
3. Turn Bots on
4. Bots will then place common flamethrower in Rare flamethrowers place turning it into a Rare flamethrower
Very overpowered