Better Furnace is a vanilla friendly datapack, it allows you to melt in the smoker or the blast furnace all the items that you can only craft in the normal furnace. Items like stone, smooth stone, cracked stone brick, cactus, terracotta or charcoal are some of them.

To be concise, all can be molten in the blast furnace now, ores like vanilla, cracked bricks, smooth blocks, charcoal, terracotta, sponge (from wet spoge), glass... But there are some items that you melt now in the smoker, food like vanilla, brick (from clay), nether brick (from netherrack), green dye, lime dye, and popped chorus fruit.

But there is more! ONLY on blast furnace you will be able to craft iron block using raw iron block, gold block using raw gold block and copper block using copper raw block. They will melt slow, so you will need the same amount of fuel to melt 9 raw iron in a blast furnace, this is to make the cost of fuel the same as vanilla, but, of course, it will be faster than melting 9 raw iron in a normal furnace.