Better Smelters Add-on 1.21+

Speed matters, especially in Minecraft Pocket Edition. With the Better Smelters mod, you'll get nine levels of Furnaces—from Wooden to Blazing. Full automation support makes them not only powerful but also convenient for any bases.

Features
Oak Wood Furnace: Fuel consumption — 1, Speed — 1
Copper Furnace: Fuel consumption — 1, Speed — 1.5
Iron Furnace: Fuel consumption — 1, Speed — 2
Golden Furnace: Fuel consumption — 0.8, Speed — 3
Emerald Furnace: Fuel consumption — 0.6, Speed — 5
Diamond Furnace: Fuel consumption — 0.4, Speed — 10
Amethyst Furnace: Fuel consumption — 0.4, Speed — 15
Netherite: Fuel consumption — 0.2, Speed — 20
Blazing Furnace: Fuel consumption — 0.1, Speed — 50
For obvious reasons, the Oak Wood Furnace will disappear within minutes, or even seconds.
How does it work?
Smelters can be used manually, just like regular Furnaces — place the materials and fuel, and then take out the output materials.
Full automation also works as shown in the screenshot below.

Crafting Recipe Examples



The Netherite Furnace can be crafted using the Amethyst and Diamond Furnaces.



