I am also finding a few of the responses for keeping Rescue in game to use a little hyperbole in their arguments too. I have been a healer for many dungeons in both Warcraft and FF14 and it is very rare for me to actually need the use of it. Probably the best reliable time to use it is to drag the LB3 player after they complete their cast so they can move again away from the fire. But even then, the DPS players tend to look for safe times to do it without needing that. The DPS players I see recently in the FF14 game are generally good about trying to respect the mechanics. Last time Rescue was used on me, it was just from a map night about a month or 2 ago. It was just to the center messing with me when a boss was almost dead anyways.

I offered a suggestion with the Neural Silencer item Warcraft has although it feels like it was still rejected even though the fear of making the spell useless seems to be unfounded on my end. Warcraft already has the item and it was used as intended for times a troll was there. Last I was in dungeons there, most players didn't have it on unless you give them a reason to do so. It is an item consumable, so it makes us think if we actually need that immunity buff up. If the party members are trustworthy, then it is imperative to keep the option open for good use of the spell. If not, then that's what the immunity item is for. The Warcraft version is a 12h buff I think which may not need to be that long. Just an hour or 2 is sufficient in the rare cases I find.