Tbh, i rather would them change the system in such way overhealing becomes rewarding to do. Forcing healers to heal more. The problem is mainly that there arent that many good ways to get that focus back, since even if it gives a DPS boost, if the healing is never demanded to begin with, a DPS remains generaly better as long as the enemies simply cannot dish out enough damage. With some casters having a revive, even that part is covered.
A few things that generaly need to be done are obviously increasing the incoming damage, and applying better ilvl caps. But there are a few more things they can do:
- Nerf self sustain significantly. There is no need for a DPS to be able to sustain themselve this strong. Even more when such healing is oGCD. For a tank some self sustain can be needed, but being able to self sustain against any boss should simply not be possible. I know this is done because of the 'healer is dead, so the party also dies' problem that it would otherwise create. Which takes me to the next issue:
- Give other classes also an option to revive others. But have additional restrictions with it. The phoenix down item used to be a major item in older FF games for this. But the many ways to revive made this obsolete. The issue here is that potions cost gil, which in turn makes them not prefered to have, but surely something can be made that resolve this.
- Make the party receive boosts depending on party health (or punish low health - since it requires some more reworking its effectively the same). Sure, the healer might barely get any benefits on his own. But if the party being at full health gives an over 10% DPS boost, compared to a party at 50%. It means that quick healing can effectively grant more DPS in the end.
Enmity management was only a thing on pure healers as their regens could cause issues. Barrier healers didnt have this issue for that reason, so the fix here is to simply balance the 2 types, and on that fine. But i agree, it sadly means that excessive overhealing isnt punished anymore (overhealing on its own isnt an issue when you arent going to be using a dps spell within the next 2 seconds and have plenty of mana).
But yes, a way to punish (excessive) overhealing would be nice to have, simply because its a teaching mechanic to get a healer not blindly spam healing and ignore dps. Emnity was a realy good way to do this as the punishment was directly visible (you got attacked).