Combining some buttons into one

[SamRF]

The thing is, combining those buttons can still lead to more intriguing gameplay. If the devs want to keep the button count within a certain range, dead skills that serve no purpose outside of niche uses that could just as easily be merged with other skills block actually unique and rotation-enhancing skills from being added.

Like, between the lines can't be used outside of when Leylines is active, so whats the point of it being a separate button? leylines just went on CD to even use between the lines, so its not like its blocking you from using Leylines again. Merge the two, free up a button slot, then add something interesting in its place that enhances the job further.

Geirskogul <---> Nastrond is one of the best ways they've implemented it and it should be standard across all skills that have their effects locked behind the use of another skill. (Req -> Confitteor, Death flare + Enkindle Bahamut/Phoenix being all one button due to mutual exclusivity, all three parts of Gnashing fang being condensed to a single button so it's two buttons instead of 4, etc, the list could go on for a while.) Given that the alternative is that they straight remove stuff to fit their button criteria, condensing keeps all the skills around while allowing new skills to enter the fray, while also keeping the button count the same.

Good argument and I might be okay with it if it meant we'd get more unique buttons and job mechanics, but not sure I'll enjoy this as much in practice as I'd think right now.

The immersion aspect will still be violated and it's a line which hasn't been crossed yet, and maybe devs want to keep it this way out of having a principle and logic in place. I don't know what Geirskogul is, but looking it up I'm assuming it's like SMN Fountain of Fire and Brand of Purgatory from the Fire Bird trance. How I interpret that, is that this stance you go into transforms some of your current abilities into a more powerful one which makes sense from an immersion perspective, it's the same ability and does the same thing essentially but it's a more powerful version, due to the stance you're in.
Enkindle isn't like that since it's a seperate action that doesn't have anything to do with the summoning button, it's giving a command for an attack which doesn't summon it, while the alternating between Phoenix summon and Bahamut summon does make sense since you're doing the same thing for both actions but just a different version.

Again, I think devs consider this immersion principle and haven't been willing to violate it so far (maybe to avoid slippery slope?). It's easy to neglect immersion and having a sort of logic to your abilities when you still have it, but I think violating this would for some make the rotation feel less satisfying and less immersive than they'd think it would beforehand. It may also get more confusing if you're changing too many buttons into dual action and dual purpose. Some perhaps also value there being set "principles" instead of inconsistent change in structure and ability function.

To also respond to your remark about PLD and to give another example: I enjoy the fact of Confiteor being a seperate button because it feels more like a standalone and real (powerful) ability you get to tap every now and then, and feel good about it. While if it would just become a replacement for Requiescat when you're in that window, I'm sure it wouldn't feel as special just tapping that button again to get this Confiteor, while also considering that it's a different ability from Req in terms of function, so for that reason it'll also be illogical and thus perhaps less satisfying to me. Maybe it's silly and maybe it's nonsense since it's difficult to convey what I mean, but try to consider it.