When the Face Target option is activated, the player character will immediately turn to face the main target. If the player character is in motion when Face Target is activated, the character will come to an immediate halt.
Not being a Mage myself nor have I fought Ifrit yet so I may be wrong but the bolded part sounds like a good thing...is it?

I interpret that to mean you can run towards a player who needs a Cure and hit H to lock on, halt and cast.