With this update, this plugin is now future-proof until at least Minecraft 1.58 (assuming one new trim per update).
Changes
The internal list of existing armor trims is no longer hardcoded, and is instead generated by finding all items with an ID ending in _ARMOR_TRIM_SMITHING_TEMPLATE.
Fixes
Fixed a bug where if a player was revived, their armor would be trimmed in emerald material even though they were on 1 life.
Fixed an exception in the console if you clicked on an empty slot in your inventory while having the armor trim choice inventory open.