Hi there, thanks for reporting this. After a bit of testing I can say that you are indeed still using resources using this method. I know it looks like you don't as backpack crafting is cheaper for clay than forge crafting for some reason but if you spam your "w" while crafting at the forge and watch your brass in the smelting spot you'll see it quickly loose 6 brass at a time whenever a spot clears up in your que. Smelting only uses one brass at a time. You can see even in your video the brass in the smelting spot quickly drop by 6 brass whenever you start crafting and then it will look like it's not using any brass while your que is full. So when you click the recipe from your backpack, it will use the brass and clay from the smelting spots in your forge but not the materials that you've already smelted and when you craft only one of something at a time that uses few resources, the time it takes to craft and the time it takes to smelt can almost cancel each other out but you do still use materials. I hope this clears everything up for you.
