I'd like to suggest:

1. Adding a visual indicator for each job's major cooldowns
For example, Tank's mitigation and invulnerability, WHM's Benediction, DPS's mitigation and raid buffs
2. Letting players "Ping" their abilities to tell party members they are on cooldown
I came up with the idea from MOBA games and thought it would be a godsend in FFXIV high-end duties, doing so in said games would display a message in chat telling others if a certain ability is currently on cooldown or not and how long until it will be ready

The reason for the suggestions is that I used to clear Savages with PuG and recently joined a temporal static, after that experience, I feel that it's a totally different game with and without communication.

In PuG, we can't communicate as quickly and clearly as through voice channel in static. There isn't enough time to type during a fight, so I often have to guess how party members are going to solve the next mechanic, are they going invul or not, are they tank-swapping or not etc.

As there tend to be numerous accidents in high-end duties, things don't always go as pre-fight discussed, that's where timely communication is in great need to come back from a dire situation.

And it's why I'd like to suggest adding tools for PuG to communicate more easily, I think it would make high-end duties a lot more enjoyable for those not in a static.