Use of furnace types

Furnaces and furnace types ie smoker and blast furnace should only be able to pick up items it can smelt. For example raw meat for smoker, ores and armor for blast furnace. This feature is nearly already completed with the fuel version of the system. Only burnable objects can be pulled into the side. This feature allowing only smeltable items to go through the top of the furnace type would increase the ability to sort items with the ever growing number of items in the game.