Non-machine with possible input, output, module and fuel inventories

[Plop and run]

An entity that can have all inventories a furnace can have, except it does not run recipes automatically. Keep the crafting process (progress, animation, sound, power consumption, fuel burning, etc), but not the logic (when to start crafting, input consumption, result production). Mod authors would specify what can be inserted into the input slots, but not crafting recipes. They would implement their own logic, like when each craft starts, what the machine does, how it consumes and populates the input and output inventories, etc.

A furnace is not always a solution because there is not enough control over several important aspects of its behavior. For example:
- When does the craft starts? There is no way to delay it when there are enough ingredients. You don't even get a tick when one craft has finished and the other did not start yet.
- What happens when the craft finishes? This is not as bad, because you can inspect the output slot every tick and deduce that the craft has finished, however this solution is hacky and the UI is not great (think of the delivery cannons in Space Exploration).
- There is no way to get the item stack on which the machine acted. In some cases (item has tags or inventory) this information is relevant to the process.
- Maybe there is no crafting process, and the machine is just a fancy chest that outputs items in order they were inserted.

[BraveCaperCat]

This is a great idea - it would improve many mods that currently have to use a chest instead of a machine for various reasons. (in particular, having a million different recipes you want the machine to be able to perform) Though, I'd want to be able to make it furnace-like with more than 1 input slot, rather than just the 1 input slot.