Describe the bug
Storage units set to pull items from furnaces will attempt to pull from every slot regardless of what face of the furnace the storage unit is put on. There is one exception, that it will not pull from the furnaces fuel slot if placed on the bottom of the furnace.

Steps to Reproduce

1. Put furnace down
2. Load with fuel, items, etc.
3. Place storage unit on any side (as mentioned, bottom doesn't pull fuel)
4. Set item to auto-input from furnace
5. Storage unit pulls all items regardless of slot

Environment (please complete the following information with the version):

• Minecraft: 1.16.1
• Mod Loader: Fabric

Additional context
Not 100% sure if this is a bug or just a feature not added but figured I'd post here since it has a slight variance with the furnace being on the bottom. They should function almost like vanilla hoppers when used on furnaces and only pull or push items into the slots designated by vanilla rules (top for input, bottom for output, left for fuel, sides/back for fuel). Perhaps make one of the sides for fuel only and set another side to remove everything in case someone requires that functionality?