What Healer kit (not encounter) change would make GCD heals NOT bad gameplay?

[Absurdity]

The problem is that even if we transferred most of the potency to DoTs to make GCD healing healing less punishing or reduced the amount of oGCD healing it still wouldn't make the job any more interesting.

As Semirhage has already said, most of the healing kits are simply incredibly boring, be that GCD or oGCD. They're all "Heal target for X potency" or "Heal entire party for X potency", there is no synergy, nothing but "Make HP bar go up by X" and the skills that break this mold are few and far between.

If they wanted to make GCD healing not only viable but also actually interesting we would need more skills like Macrocosmos, Panhaima, Time Dilation, old Celestial Opposition or, funnily enough, Free Cure (except actually useful).
We would need more skills that require some thought to be effective or the ability to have our basic healing spells enhance or unlock other, more powerful, spells.