Problems Hopper automation on GUI block

So we made a kind of custom Furnace and we want to make it automatic by using hoppers. 
We made the two input slot only to put items and the output slot to take items. 

So it works fine but the problem is hopper sets items where they dont belong and we want to set what items goes where.
The GUI config to restrict items related to slots don't work in here. 

I rode its a feature they didn't added yet but they where old threads so if someone knows if its possible nowadays we would appreciate the guidance. 

Best regards,