I'm not sure how many people this speaks for, it might just be me, but I've always really struggled at connecting icons to meaning - I have a similar (though much smaller) issue with faces, but icons are the big one, especially in MMOs where they tend to look quite similar and all blend together a bit.
That doesn't normally stop me from playing, I've done some savage raids in XIV and equivalent things in a couple of other MMOs and not really had an issue because the position of the buttons on the screen (and on my keyboard) negates that problem.
Then we got Viper. This is the very first class in any game I've played that I legitimately cannot follow because, for some unknowable reason, its 8-part combo is reduced to 2 buttons that not only change but you're meant to weave between depending on what step you're at. Never once had an issue with freeform SAM in ShB, no issues with MNK or DRG, but I just can't follow this one, the buttons lose meaning within a couple of cycles, I don't understand how this was a conscious decision and got through testing. I understand that the option to combine it helps some people as it reduces button bloat, but I strongly feel that doing so at the cost of some people being able to use the class at all is not a good trade. Especially that, even accessibility issues aside, you can't lay things out on a hotbar and see what things do while planning out what order to click them in, where you can organise them in a progression as you learn the rotation. You need to either have the already ordered Abilities screen open and read them and try to remember when they happen (again, big issue for some people with that) or you need to click a button, read what the next step is, click it, read what that does, then try to formulate your memory of what you clicked into a rotation (which, yes, is many times worse).
We've been given the ability to split other combined buttons that have 2 abilities sharing a button - why isn't this the case for the massive 4 abilities that then need to be combined between each other in VPR?
So, please, give us the ability to split that horrendously massive stack up into separate buttons. With PvP, I've just avoided it entirely for this reason and it doesn't impact the main chunk of the game, but this is seriously affecting my (and I suspect a few other peoples') ability to play one of the new highlight classes in the game. That's not really acceptable given how there's an extremely easy fix that was implemented in this very update to the game, just not applied to (arguably) the main button stack that suffers from it. By all means, keep it combined by default, I'm sure that helps a number of people too. But forcing it to be combined when the icons are this similar is kind of baffling.