Stoneskin Playstyle & Uses

A question(s) to players who are doing the Coil:
How often do you use Stoneskin? Where and when do you slip it into your rotation?
I use it prepull and sometimes during the fight, but the slower cast compared to Cure 1 and 2 make it seem very lack luster. On a tank it can do a bit more then a Cure 2 but again the cast time seems to make it feel more risky since it is not a ton more from what I have seen.
Perhaps some first hand use and theorycrafting on when and on who you use it during a fight would be nice. I could just be in a Company that has tanks who aren't using their CDs well, or perhaps my fellow healer and miy skills aren't up to par yet, but On say phase two of Turn1 and the last boss of Turn 2 have me spamming tanks and the extra cast time of Stoneskin nearly kills the tank.
Thanks for any advise on this Ability that so far seems nearly useless to me.

Haven't done Coil as a WHM yet, but the use of Stoneskin is fairly worthless during fights, exactly because of the cast time. The time is spent better just spamming cure.

As a PLD in Coil, I'm going to take a heavy amount of damage regardless of how well I utilize my cooldowns. When Aggro swapping in Turn 2, I'll just cast Stoneskin on myself.

In turn 1, if my tank gets his HP topped off, Swiftcast is up, and no one else needs a Regen (a lot of ifs), I'll Swiftcast Stoneskin the tank.

I've typically associated Stoneskin with enmity management or maintaining Cleric's Stance.

In Coil, I haven't had enmity issues and with default healer Accuracy being so low, I tend to stay out of Cleric's Stance now. Otherwise, Stoneskin tends to be pre-cast before combat in Coil situations.

Stoneskin is largely a pre-fight spell, allowing you a bit more breathing room for the tank to get hate at the start (Or for you to focus on laying down some DoTs instead of healing). That said, there are a few uses in-fight:

For healing, it's not going to outclass Cure II (Which has the same MP cost) unless you're fairly undergeared AND the tank is very well geared.

It can also be considered a heal that ignores the maximum HP. After all, there's functionally no real difference between mitigating 300 HP and healing 300 HP (barring enmity). This means it can be used in situations where the tank may want more HP than their max HP, such as for King Tonberry's "Everyone's Grudge" and Titan's "Mountain Buster"

Finally, if stoneskin is sufficient to reduce damage to 0, you can use it to avoid things such as knockback and poison.

Im maining my pld for the time being. I just stone skin myself. When you think about it, a self stone skinning tank in titan is a blessing for healers. Especially before mountain breaker.

I honestly only use stoneskin in combat during 4-man dungeons. I swiftcast it onto the tank along with regen to give me time to DPS with cleric stance up. I typically don't try it in 8-mans, and in Coil, I save swiftcast for cure III.

Prefight is pretty much the only time I use it during coil. Also will cast it when the tank hits hollowed ground or during turn 1 snake boss after one of the snakes die.

In turn 1 and 2, I have not found a time that makes stone-skin mid-fight worth while. Yes there are times it could be benifital, but those are they times (snake boss split) that I can not waste mp or time not healing up the tank to full health. Although stoneskil might help buffer some damage, I do not see that the mp-cost, cast time, damage reduced is worth not casting the cure (2) i would have in its place.