Actually press the buttons.
Seriously, Dissipation isn’t a bad cooldown. Learning how to use it isn’t going to magically make sense until you actively try to make use of it. It’s DPS and healing positive but actually requires thought. My problem with Quickened Aetherflow is that it trivializes SCH’s Cooldown management. That also includes Fey Union, which would be up way more often. It doesn’t make the class ‘hard’ as billy assumed I meant, it makes it brainless by completely mitigating the need to manage Aetherflow actions or Fairy Gauge at all. That’s my problem with it. Healers already barely have any resource management beyond their GCDs, why would you want to further trample on that?
EDIT: Was at work when I first wrote this, but to prove my claim that Quickened Aetherflow trivializes SCH's Aetherflow management, I'll demonstrate that it will do so even with Kabooa's suggestion to reduce it to 45s.
Stacks generated:
Aetherflow 3/45s -> 12/180s.
Recitation (Indom or Excog) 1/90s -> 2/180s.
Dissipation 3/180s.
Total: 17 Aetherflow stacks, 2 are limited to Indom or Excog.
Aetherflow spenders:
Sacred Soil/Indom 2/30s -> 12/180s
Excog 1/45s -> 4/180s
Total: 16, not factoring the use of on-demand cooldowns such as Lustrate or Energy Drain.
Now add another 25 seconds (Dissipation + Recitation's effect on Quickened Aetherflow as it existed in SB) onto that, which adds another aetherflow cycle every 6 minutes, roughly speaking. There's no reason to add such a ludicrous buff onto it again. SCH is already -barely- limited by Aetherflow as is. At that point the only reason Aetherflow exists is to add Energy Drains and Lustrates. We might as well add that in the form of an actual DPS cooldown instead, rather than bolster SCH's maximum healing throughput as a knock on effect.
As for how to improve SCH's gameplay, merge Dissipation and Summon Seraph, in addition to my previous suggestions (add a charge-based DPS oGCD, bring back DoT management). When you unlock Seraph give Dissipation 2 charges, and lower its cooldown to 90s. Force it to alternate between Dissipation and Seraph every other use. Forcing people to use one in order to get the other will make it clear why you should be alternating both. Another idea would be to make Deployment Tactics act as Bane when used on an enemy, with no drop off. That way you can justify leaving the cooldown alone.