One thing they can do is make it possible to use aqua shards to upgrade a high tier +10 item to its EX version once you have it at max level. Maybe they could also add the ability to use fodder equipment in order to add a +1 to an item of the same type. That way you could either grind fodder gear into bond crystals or use five of those +1/+2/+whatever rings to turn a +9 ring into a +10 ring.