Fast Smelt

I made this because I don't like waiting for a lot of items to smelt, especially when I'm out exploring.

With this datapack, smelting on Furnace, Blast Furnace, Smoker, and Campfire takes only 1 ms per item. This means Blast Furnace and Smoker are pretty much redundant since regular Furnace now smelt just as fast. And it works with all smeltable items.

Installation

At the creation of a world

Here is how to install a data pack when creating a singleplayer world:

1. Open Minecraft.
2. Click on "Create New World".
3. Click on the "More" tab.
4. Click on "Data Packs".
5. Drag the data pack into the Minecraft window. It should be a .zip file or directory.
6. Click "Yes" on the confirmation screen.
7. Move the data pack to the right hand side of the screen by clicking the triangle on its icon.
8. Click "Done" and continue creating your world, then click on "Create New World".
9. If the data pack has a correct format, it would be enabled in the world. If you have enabled cheats, you can verify by typing /datapack list enabled and find an entry named [file/your data pack file/directory name].

Alternatively to step 5, you can navigate to your system's temp folder and find a folder with a name starting with mcworld, then you copy the datapack there (this is not recommended to non technical users, but it is useful if for some reason you can't drag files or the open folder button doesn't work for you)

In an existing world

Here is how to install a data pack in an existing singleplayer world:

1. Open Minecraft.
2. Select the world you want to install the data pack for, click on "Edit", then "Open world folder".
3. Open the folder named datapacks, and put the data pack into it. It should be a .zip file or directory.
4. Type /reload (if you have enabled cheats) or press F3 + T if you are in the world during the installation.
5. If the data pack has a correct format, it would be enabled in the world. If you have enabled cheats, you can verify by typing /datapack list enabled and find an entry named [file/your data pack file/directory name].
6. If it doesn't work then reload Minecraft.

or check Minecraft Wiki for further details.