lv60 Black Mage Rotations?

[Zerathor]

I was under the impression that B4 (umbral hearts) wasn't actually contributing much to the rotation. Was I misinformed?

b4 is kind of strange. its more of a tool to ensure you have maximum mp to cast 6 f4's (as during your blizzard phase depending on mp tic timing, you generally need 3 gcd's. like b4, t3, foul. or at 60 b4 t3 b1). if you're given a scenario where you can skip it, and it not mess up your fire rotation afterwards, and the one after that, you can skip it and do only 5 f4's for a slight gain. But that kind of scenario requires instant mp proc, and thundercloud procs as well. and at 70 ensuring you'll have foul ready for the following blizzard phase when you'll likely have too low mp to cast b4. in general, its not a bad spell though. skipping b4 requires a little thought, but using it every rotation wont lose you much and keep your dps reliably high without requiring much thought and reaction.

In general to skip b4 is a minimal gain with mild risk, and still requires rng to even think about doing. and messing it up once by needing to wait for an mp tic will outweigh any gain you obtained. In general I'd say it isn't worth it unless you're extremely comfortable with blm and the fight you're in.