Have you ever found/enchanted a really good gold/iron item that you wanted to keep the enchantments for? Smithing Expansion: Resmithed adds new smithing templates to make that exact specific situation simpler!
First, craft a Blank Iron Upgrade Smithing Template with 7 cobblestone in a U shape. Combining this with a gold ingot will give you an Iron Upgrade Smithing Template. Inserting this into a smithing table with a golden tool/armor of choice and an iron ingot will grant you the iron variant of that tool, keeping the enchantments of the golden equipment on it. This can be repeated with a Blank Diamond Upgrade Smithing Template, crafted with 7 cobbled deepslate in a U shape. Combining this with an iron ingot will give you a Diamond Upgrade Smithing Template, which can then be combined with iron equipment and a diamond to grant you the diamond variant of that item, still holding the enchantments on it. You can then proceed with upgrading it to netherite and boom! You get the enchanting power of a golden item with the strength and power of netherite.
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