Updated to 1.20.x, works for 1.20 and 1.20.1 :)
Compatibility fix for GeckoLib (backported from the 1.18.2 version)
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Updated to 1.17
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Updated to use Trinkets API instead of Curios API
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All modded armor is now compatible without requiring them to be added to a tag
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Instead, there is now a tag for a blacklist if you don't want certain items to be used as cosmetics
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There is now a tag which defines items which are always visible when equipped as armor, and are not overriden by items in the corresponding cosmetic slot
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Head items (player heads, mob heads, pumpkins, etc) are now equippable in cosmetic slots
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The items don't all have a line in their tooltip which says they can be equipped cosmetically