Today I realized that buffed cokingplant is different from all other buildings when it is buffed. All other buildings I have takes the same amount in but double the output, but not the cokingplant?! It doubles all. So a lvl 1 plant unbuffed takes 1 log and makes 1 coal, a buffed takes 2 logs and makes 2 coal. No other building, what I can find, do like this. Is this a bug?