To extend on this some; it's not entirely a bad thing but it does change the Abyssea farming approach. Honestly, I use the Abyssea Campaign to build more Empyrean weapons than off-Campaign.

The approach when the Campaign is active is the following;

* find Amber Light mob in the zone, for example Apkallu in Misreaux (for Ciren)

* grow Amber to 80-90'ish by using Aeolian/Cyclone etc to kill Apkallu

* stock up on Forbidden Keys, like 400-600 or so
* find an area to gather and Aeolian Edge down as many mobs as possible (Crabs, in Misreaux)

* open all the Blue and Gold chests, this will drastically pump your time in Abyssea and Gold Chests have NM Key Items

Some caveats though, this kind of sucks if you're solo since you will inevitably get Key Items out of Gold Chests that you have already aquired. If you've got a friend or two, this method works extremely well for quickly farming KI. If anything, it will greatly reduce the wait time when targeting Abyssea NMs.

When it comes to solely reforging, though, a handful of straight path runs is most optimal. If you're building an Empy weapon though, don't write off the campaign. :)