Comment 3 for bug 1252167

In short: Reducing the target quantities for trunks and increasing those for coal does not help.

Longer answer:

Having some trunk is important. After this change, burners shut off if there is less than this much trunk.

Without this change, the target for trunk does not really matter. If there is demand of coal, the burners easily hog all spare trunks. Of course, if the player has more than enough coal, then the burners stop.

In my experience, it is rather common scenario that a player uses most if not all mined resources to imrove soldiers, and still would like to build. In such case, the burners harm the economy.

The downside of this change is, of course, that burners do not work at all if the number of available trunks is below the target value of the economy. I do not see this a problem, since even in maps like Fellowships one can reduce the target number of trunks when the need for coal exceeds the need to have trunks at hand.

At least some people do build burners also if they have access to some coal.

Yes, this is a feature request and not really a bug. I am not at all surprised by your verdict on b18.