Let's sit down and think about this. Forging is the tempering process of requiem and altiverse equipments. Unlike actual temper, it takes the better range or fails. Primary is the equipment that is being enchanted by the secondary equipment. Primary doesn't destroy itself when forge fails. I don't how simple I can explain this, but stats are given to the primary, but compound and refinement does not pass through, because its on the secondary equip. The secondary one is destroyed from the process of transfer.
Best example I can give.