Adds alternative recipes that craft Steel and Electric furnaces from the previous tier of furnace, dropping the ingredients that furnace already contains. Unlocked by the same research as the normal furnace recipes. Also gives you the option of requiring crafting the whole chain instead of directly crafting each tier.
Small changes concerning balance, gameplay, or graphics.
Upgrade Stone Furnaces to Steel, and Steel to Electric, without paying a second time for everything the old furnace already contains - No more chests full of old, useless furnaces. Also gives you the option of requiring crafting the whole chain instead of directly crafting each tier.