So furance fuel was nice in a sense that is allowed you to get past technical problems with the code, but now that we have the new flags, I find myself wondering if it is really necessary. Other mods like The North and Small Village get by just fine with using charcoal directly, and the transformation into furnace fuel seems kind of an illogical and unnecessary step.
One possibility is to make charcoal the default industrial fuel for everything from distilling to smelting. Maybe for smelting metals we toss in coal as well.
Another way is to make firewood the easiest and cheapest fuel to produce. Charcoal is made by refining firewood and is a more powerful fuel. (You get more charcoal per firewood unit spent.)
Coal meanwhile is a more powerful industrial fuel. (You need less coal for industrial recipes) and can be refined into coke to use as fuel for a much greater return.
Like say for ten units of charcoal you only need five units of coal, and for fuel production you get six units of charcoal for every four firewood, while you get ten units of coke for every five units of coal?
