BLM's Blizzard 4 needs a potency buff

[LeonKeyh]

Uhh...I don't think we need any buffs.
We're already the top dps.
Though ofc I wouldn't say no but kinda don't wanna be that op to the point everybody is playing blm.

But, BLM is top DPS?

Guys. Read the post. This isn't about a meaningful increase to DPS. As it stands, casting Blizzard 4 assuming that you're already full mana isn't worth it (and it looks like it might not worth it if you are below full mana either). It's better to just get out the 4 Fire IVs and a Despair instead of 6 Fire IVs that Blizzard IV allows for with a Fire I in between.

They're not asking for "more DPS" just for the sake of more DPS, they're asking for a potency increase on Blizzard 4 so that casting Blizzard IV is ALWAYS worth it. As it stands, Blizzard IV isn't worth the cast, but increasing the potency would actually make it worth it and make the BLM's intended rotation the ideal rotation.

tl;dr:

The Blizzard III / Thunder III / Blizzard IV / Fire III / 3 Fire IV / 1 Fire I / 3 Fire IV / Despair rotation isn't as good as
Blizzard III / Thunder III / Fire III / 4 Fire IV/ Despair

Increasing potency on Blizzard IV bridge the gap between those 2 rotations with a minimal DPS increase.

This thread misses the point of Blizzard 4. You have to typically wait for 2 ticks of mp gain to get full mp, which you obviously want.
Blizzard 4 was created in order to satisfy that. In fact, many times you need a little under 3 GCDs if you're unlucky with server ticks, which is also one of the factors of why people use thunder during ice phase.
You don't use blizzard 4 for it's sweet damage or anything like that. In fact, I'd bet if blizzard three just gave you a full mp bar upon casting, you wouldn't even want the umbral hearts.

Blizzard 4 is there because BLM needs another skill to use during ice phase to fulfill server ticks. The dev team saw this, and gave them a low damage utility spell in that slot.
If you already have a full MP bar, like say, in your opener, it's not necessary to fluff up your blizzard phase with another cast.
Blizzard 4's "issue" as described by people here is literally that it fulfills it's role of a utility spell to cast while waiting for your MP to come back extremely well.

It's wonderful at the moment. It needs absolutely no change whatsoever.

This is a good point, but according to Rongway's math, it looks like the short rotation is still better than casting Blizzard IV in the scenario you described where you need another GCD to hit that second tick. I would wager a guess that given the cast time and GCD of Blizzard IV, it would likely be better to just wait a little longer before starting the Fire III cast than it would casting Blizzard IV beforehand.