Variants-CIT

• Modules can now change the texture of equipped armour, by overriding the assetId field of the equippable component. These modules will collect "equipment" assets instead of Item States and Baked Models. Non-humanoid equipments are also affected, varying with your version of Minecraft.

See: Wiki

• Added durability module.
• Added options matchAll and validate to the regex transform.
• Added sanitize_auto transform.
• Added rich_text_array data type. (E.g: lore component)
• Added auto data type.
• expect now accept arrays.
• nbtPath is now optional and defaults to using the whole component as data.
• Added simplified mono-string syntax for ItemComponent properties.
• Format variables now accept upper-cases, numbers and low-dashes
• Marked module types custom_data, entity_data, bucket_entity_data or block_entity_data as deprecated. (Use component_data instead.)

• Fixed a crash when providing bad regex substitutions.

• component_format variables may now take a fallback.
• component_format variables can now use regex.
• Fixed a crash on malformed json.
• Fixed overly lenient json parsing, often failing silently with a fallback, instead of showing an error in the log.

• Fixed crash when a module targets a non-existent item type.

• Ported to MC 1.21.5
• Removed Item State extensions introduced in v3

Lots of changes in how Minecraft handles NBT and item components. Be on the lookout for unexpected behaviour changes.