Help with BLM Rotation

[Thela]

Okay so the 68 trait is for when you have umbral hearths up only. You know when you cast Blizzard 4 you get 3 stacks of umbral hearths reducing the mp cost of 3 fire spells in astral fire. Casting flare will consume all 3 or however many are remaining but will not reduce your mp to 0 basically allowing you to cast 2 flares before your mp hits 0 if you have any umbral hearths up. If you do not have any umbral hearths when you cast flare your mp will still go to 0.

So for aoe pulls you will want to do something like this:
At pull: Blizzard3->Enochian
Umbral Ice: Thunder4->Blizzard4->Fire3
Astral Fire: Triplecast if available->Flare(Umbral hearths goes to 0 here)->Flare(MP goes to 0 here)->(Convert if available)->Flare(MP goes back to 0 here)->(If Max Ether is available and you want to use it you can here followed by->Swiftcast->Flare)->Transpose->(Foul if available)->Repeat from Umbral Ice phase.

Depending on target count you can cast 2xFire4 or 2xFire2 before the first flare leaving you with still 1 umbral hearth so that the first flare doesn't consume all your MP.

As for not seeing many flares in expert dungeons that sounds weird, there are multiple aoe pulls in all dungeons and if you're running with a BLM they should be using flare alot.