Don't re-opt it anymore. It should be good now. Changing the blue option from max to min would only make a negligible difference in the end result.
Also, don't cube down the max. You'll end up using up a bunch of dura regaining the Lv5 and only getting a few percent (if any) out of it. You're better off using that dura to resuper once the enchants are Lv10. However, cubing the fire is OK since it's near-useless like you have already mentioned.