I don't mean to be rude but if what you want as a healer is to be trying to pump out as much HPS as possible, go play WoW. FFXIV's healer design (and this won't change with whatever healing overhaul 5.0 brings) is about taking breaks from doing damage to cast healing spells, ideally not having to stop DPS at all. Only healing and just idling between Cure/Physick/Benefic casts, even if you're keeping your tank(s) alive, is playing the job *far* below even 50% job proficiency. Assuming your tank isn't literally wearing paper towels for armor in Ghimlyt Dark, there are no encounters in the game designed for healers to be putting all their GCDs into healing.

I agree that WHM's "Stone IV -> Stone IV -> Stone IV -> Stone IV -> Stone IV" rotation gets a little bit tedious by the point in the game where enrage timers are a factor, yes, but I fear that further complicating healer DPS would just give people more reason to think healer DPS is just a tryhard Ultimate-level optimization. As a WAR player, I can tell you that I've gotten sick of my DPS rotations being interrupted by overlong boss phase change gimmicks and it's made me almost not want to play tank at all. As a healer, that would hurt even more in the form of having to actually heal occasionally.

I don't think that the kind of changes they're making to healers with 5.0 will have DPS skill ceiling in their scope. It'd need a pretty big dynamic shift to make that feasible.