Okay, I'll make this more straightforward. I don't like the mining system in the game. I don't like that you have to rely on intelligence and knowledge of the other players when it comes to such a sensitive thing, such as securing the door. Often I see 2 techs to drag about it, who can better mine the door, mines are disappearing and before they agree to so the refinery is gone!!!
Suggestion:
Step 1:
The mines wont be able to deploy in the buildings anymore.
Step 2:
The door will never ope