Currently, the item updater will upgrade items when the lore or maximum durability of its corresponding custom item changes. However, changing the durability prefix in lang.yml will not cause an update, which causes items to keep the old durability prefix until their custom item is modified, or it loses durability. It would be better if changing durability-prefix would also update existing items.

Durability lore is no longer used in KCI 13 (except for very old MC versions), so this issue is no longer relevant.