It's a pity he can't process ores. He would be able to gather more rare elements directly from the ground if he could, to make special steel. Although I suppose he can take pig iron and turn it into better steel than we can make in RL, without any additional elements simply by giving it magical properties, so perhaps it doesn't matter at all. I guess he still needs to have an earth arts user to process bauxite for him to get aluminium, though.