BLM QoL suggestion

[Seraphor]

Which is significantly lower than the 540 potency of a Fire IV in AF3, and since you are MP and time limited in AF, it is not worth the sacrifice.

As I said, you shouldn't use it if it would cause you to drop Enochian , so the 'time limit' of Enochian isn't an issue, or rather it's one of the few exceptions that you shouldn't use it and can work around.
It costs no MP, so the MP limit for your Fire spells is a non-issue.
It's higher than any Ice spells, so for 0 MP it's nothing but a bonus.

[Acidblood]

As I said, you shouldn't use it if it would cause you to drop Enochian , so the 'time limit' of Enochian isn't an issue, or rather it's one of the few exceptions that you shouldn't use it and can work around.
It costs no MP, so the MP limit for your Fire spells is a non-issue.
It's higher than any Ice spells, so for 0 MP it's nothing but a bonus.

It's not (necessarily) about dropping Enochian, it's about only being able to fit so many spells into an AF window before you have to refresh it with Fire 1, and every Fire 1 costs you a Fire IV (in terms of MP). Thus, if you are spamming Thundercloud (i.e. beyond 1 per AF rotation) you are essentially swapping a Fire IV for a Fire 1 + Thundercloud, and that is a bad trade; 540 / 2.8s = 192 PPS vs. (324 + 390) / (2.5 + 2.5) = 142 PPS.

Additionally, by my calculations a standard rotation has an average active (i.e. excluding DoT) PPS of 162 with 1 Thunder III cast in UI and 1 well timed Thundercloud proc in AF, which results in 100% Thunder DoT uptime... and since Thundercloud only has an active PPS of 156 it is in fact a DPS loss to spam it (regardless of phase). Also interesting; if you ignore Thunder entirely it results in a rotation with a PPS of 172*; so a BLM ignoring Thunder would actually do more DPS than a BLM spamming only Thundercloud (156 + 13.3 = 169.3 PPS).

* Note: I do NOT advocate ignoring Thunder. For comparison a standard rotation including the Thunder DoT has a PPS of 175 with 1 well timed Thundercloud proc, and a PPS of 184 if you can manage 2 well timed Thundercloud procs.