[NOITCA]

The issue, I would think is, there isn't a way to determine if the enchantments on a weapon are created using the forge or some other magical item (i.e. Gem).

So, when a gem enchants an item, that item needs some kind of tag.

When the item is placed on the forge, the forge not only counts the number of enchantments on the item, but, it would also need to count the number of gems used on the item and subtract that from the total enchantments.

Just thinking out loud.