I don't like the need for an upgrade to pipe items in and out. Can a config setting be added that removes this as an upgrade and just makes it available all the time? (I'd be willing to code this if it would be accepted.)

furnus/pulvus works like a regular furnace even without IO upgrade.
Means input top, fuel side and output bottom.

I didn't know that; it is basically all I wanted. The documentation doesn't make that clear at all, though. Can the item be renamed to "Customized IO Upgrade” or something, and have the tooltip (and description on Curse) updated to clarify that?