With the introduction of the new research line, the doja farming is on again. How about giving the broken tagging device the ability to be repaired by tradeskilling it with another useless loot item from the same area. Perhaps combine 3 or 4 of them in order to create an area specific doja.
I understand the idea that the doja drop rate to be a bit of work on the players part. The ability to "create" a doja from broken/trash items dropping off the same mobs is a bit appealing.
Just an idea.