I often find myself, when upgrading my base, that I sometimes accidentally pick the wrong upgrade. Most times its when I’m upgrading a base to stone and I hit sheet metal instead. I think you should be able to 1. give the player the option to change back to stone (or even wood) after upgrading to sheet metal, OR, 2. Add an undo button, to fix any mistakes that you make.
Its a troll to screw you up when building. Take the metal out of your inventory, problem solved.
Not a troll…the same building rules would apply like rotating and deleting. You have 10 minutes to make adjustments, this should be one of them.
No need for this option, just do this.