I would love to see the quick chat expanded, but the current system could also use major overhaul because most of the people are not really looking at the chat in first place.

Give unique sound effects to most meaningful chat commands, right now a lot of them share same ones so you can't play just by sound.

Add additional animations/effects to the commands, like using LB% or MP% shows it as Orange or Blue floating % over your head momentarily. Using fall back and retreat could use the tracking arrows from raids to slightly point towards spawn, same for push the crystal but towards crystal. Might need different colors for quick and easy clarity. There's just so much that could be done, even some of the normal skills could use update like giving PLD Cover a clear Shield Icon on top of the target (at least for your own teammates).