Ok, I'm wonder if forge comes equipped with code that you can use to have more then 1 item you need in a furnace input slot for it to start smelting.

Ex(using items from my mod):

16 ironsticks go into furnace input slot, 4 irongoo comes out, 16 iron sticks dissappear.

Any ideas?

If there isn't anything like that(and what I see, there might not be), any work arounds?

well... if you look in some of the files, you should get a array of itemstacks(Inventory) and you could check if this with this amount are in slot a then set slot a to -= amount and set slot b to the created thing

Or I could try creating my own furnance.