Hypermeme, infinite paradox, and transpose firestarter are the big 3. These were all introduced by accident, were a consequence of QoL improvements and, ironically, attempts to kill hypermeme, and made the class worse to play while also feeling mandatory, especially in ultimates. The class didn't have any of these things in Stormblood and especially HW, and felt just fine despite the jank involved with HW enochian. Though HW BLM was its own....mess.
The reason I so vehemently attack nonstandard is because it derives as a consequence of actions the devs have taken over the years to advance the class, but demonstrably, especially with DT killing it, were never intended or indeed supported by the devs. And as it turns out, when you remove this crap from the class, it reveals the major underlying problems.
But Stormblood had a 13s AF/UI timer so short cycling only made sense on boss jumps. The flexibility of the rotation was basically choosing when to use sharpcast, whether it was for fire 1 or thunder 3, and little else. The AF/UI rotation combined after fire 1 lasted long enough to kill firestarter, so transpose firestarter didn't exist. Hypermeme can't exist without a 15s AF timer and despair, so unless you were using a foul, you kind of needed blizzard 4 to buffer for server tics to go back into AF3 with full mana anyways. So the only short cycle available was basically a thunder refresh into foul. Which itself you wouldn't want to really use if a boss was jumping for the reasons of clipping a DoT.
It was a pretty rigid rotation in HW and SB, and the major complaints coming out of BLMs was basically how punishing enochian was, not that the class was too rigid. Because the class was almost literally, exclusively, maximizing fire 4. Which was still true in ShB and EW, but the way to maximize fire 4 literally involved cutting core parts of the rotation out, which is why I call it nonstandard abuse. When you ignore core parts of a class, the class can only be badly designed. Imagine a SAM that ignores stickers, or a Monk that ignores its second and third step of the combo. Oh wait, we don't need to imagine that, that existed, it was called infinite dragon kick, and the devs killed that as well.
If you knew the history of transpose, you'd know it was never intended for use in this way. The skill started with a 15s cooldown. Even with UI1, you'd be at max mana before it came back. Transposes entire purpose, its raison d'etre, is to get you back to full mana after a pull That is its design intent especially when taken in context of how ARR BLM operated, especially before fire/blizzard 3. This no longer exists as of DT and is now a weird, orphaned ability that can still be used to abuse nonstandard, just not nearly to the same degree. My favorite way currently is thunder mage during aoe pulls and pretending HB2 and HF2 don't exist because the devs screwed up the AoE rotation that badly in DT. But, you know, when you take away the grime of neglect, you tend to find things are in need of dire maintenance. So thunder mage. We can talk about flare and the aoe rotation, but as mentioned above, the aoe rotation has never been particularly well thought out. There was an entire jank rotation related to abusing server tics with just the right timing to basically chain back to back flares by using flare to get out of UI, getting a server tick after flare registers and consumes mana, but before UI is properly ended, and then flaring again. BLM has had a very fun history with extremely poorly thought out design choices that has resulted in jank and abuses of the design. Some of them the devs reasonably couldn't have been aware of, others a consequence of bad design.
Transpose Firestarter also didn't exist until Endwalker outside of a brief stint in ARR. The buff duration of fire 3 was too short to reliably limp the buff out of the AF phase into the UI phase, do the full UI phase, and then transpose firestarter. It required getting buffed from 18s to 30s to enable this behavior. While the old 12s buff in ARR worked because you could easily fire 1, blizzard 3, firestarter proc, and then transpose firestarter was used to reclaim some of the proc's damage due to the bad netcode implementation of FFXIV combined with the state ARR BLM was in.
And the fun thing is, they didn't gut the class to me. They restored and enforced the HW and SB rotation. The best aspects of BLM, the rotation that made me fall in love with the class. And by enforcing it, we can see just how bad a position BLM is in. And, lo and behold, the bad position BLM is in.
But sure, strawman my argument. The class is easier to understand now, and just as hard to play as it was in HW and SB. Just with the added punishment of messing up causing you to drop flare star, at least 1 fire 4, and whatever gauge was in progress for xenoglossy. Which I relish in being made worse because it means the devs will maybe, finally realize that the thing holding back BLM is, was, and always has been archaic design choices made in ARR that have been coopted into a major and extremely flimsy structural component prone to breaking at the slightest breeze. You know, literally what it was in HW and SB anyways.
Non of the nonstandard stuff was QOL intended to make the job easier to play. It exploited things intended to make the job easier to play to ignore core components of the class. That is why I am positively giddy that nonstandard has been mostly killed, and I look forward to the class finally getting the much-needed love it deserves, especially as DT moves to completely kill the turret caster playstyle. But, you know, clearly a 5s transpose to capitalize on a 30s firestarter buff was in the minds of the original ARR devs when the class was designed as a proc mage.