I think they should have a system like the curx of crota for weapons. 1) The current raid (crota, house of wolves, and beyond) has a 8% chance to drop [the upgrade item, whatever it's called ]. 2) You take that item to the gun smith and he gives you a task. A super hard strike, kill a specific enemy in the hard raid, etx 3) You use the upgrade item on the gun or armor you want to upgrade to max. 4) the last 4 damage nodes are reset and you can now upgrade your weapon or armor.