Thought about this today while I was at work.
You can purchase this as a "defense building"
However, it works kind of like a money building: Every 4 hrs you can choose to "release" smoke, which will last for 2 hrs. While the smoke is present, for 2 hrs, if anyone comes to raid your base, they will not be able to see what is behind the smoke.
I dont know what radius would be appropriate. When I first thought of it, I imagined it being for the whole base, but now I've decided that would be too much.
Do yall like it or no?