In the item modifications procedure tab, there are some blocks like "get max durability of the provided item" "get damage of the provided item" and more.
However, those only work with the provided item, not for items in a GUI.
I think there should be a parameter for them so we can choose which item should be affected by the procedure block.
There should also obviously be a "current item" procedure block in the Minecraft components tab if it gets implemented this way.
This could be used for something like a new enchantment table, a tool forge or a block that smelts unused tools into nuggets based on their damage.