Couldn’t they do something like Pictomancer where the casts are normally 1.5s but certain spells or abilities are longer with higher potency? Like WHM getting a Negative Pallet type ability that makes it casts longer and stronger; or Sage doing a reverse Eukrasia.

I think it would be weird to have the same thing on every healer of course but I think it’d be a cool idea for White Mage or Sage