Not only will this have it's uses for all of the Abyssea burned melee jobs to become usable, but this should help people chasing their blue numbers in skills obnoxious to grind such as Guard and Parry. Also great for those who need to skill a weapon for Proccing Red which they'd normally not use.
confirming drop from Zeruhn Mines. Got after 9h of farming and obtaining level 3 treasure chest finder. Fastest way to obtain solo is to do FoV ops for treasure chest finder level ups. Otherwise gold chests drop too rarely.
As low as the increase appears to be, hard to justify spending 12+ hours farming unless you combo that farming with skillups and breaking trial weapons. Keep in mind, the purpose of this ring would be to save time, but as it is, doesn't really save much.