I spent some time to better help wrap my head around what exactly is going on, and have concluded that perhaps healing up to 175k HP per GCD is a little too much.
The easiest solutions mentioned are limiting the 400 potency heal to once per action, or add diminishing returns on the aoe portion. This would make it basically on par to what PLD currently has built-in. Fair enough. But I do have another suggestion that would solve most issues people seem to have, I think. It's just a little more complicated and includes something of a compromise:
Nascent Flash
Grants Nascent Flash to self or target party member.
Nascent Flash Effect: Reduces damage taken by 10%.
Duration: 8s
Additional Effect: Grants Stem the Flow to target, reducing damage taken by 10%
Duration: 4s
Additional Effect: Grants Stem the Tide to target, nullifying damage equivalent to a heal of 400 potency
Duration: 20s
Cooldown: 25s
Thrill of Battle
Increases maximum HP by 20% and restores the amount increased.
Additional Effect: Increases HP recovery via healing actions on self by 20%
Duration: 10s
Additional Effect: Grants Bloodwhetting ( new buff )
Duration: 8s
Cooldown: 60s
Every single-target weaponskill:
Additional Effect: While under the effect of Bloodwhetting, restores HP with each weaponskill successfully delivered
Cure Potency: 400
Every AoE weaponskill:
Additional Effect: While under the effect of Bloodwhetting, restores HP with each weaponskill successfully delivered
Cure Potency: (~130 approx)
This should allow it to continue to scale up with mob count while still keeping it relevant and grounded compared to current output. Perhaps averaging ~50k per GCD compared to ~175k on large packs, and the same performance on ST. Increasing the CD via Thrill does significantly reduce this effect's uptime, but gives meaningful extra funtion to Thill (as well as inherent synergy) and with 60 sec CD it will still be available at least once per dungeon pull and for every TB. This change additionally removes the "impacts" from healing a secondary target, which ultimately no tank has a right to excel so brilliantly at. RIP blue healer.
It's still an incredibly hefty nerf but does keep the flavor, interaction and viability of the mechanic well in tact. Feel free to share thoughts, or math considerations beyond my rudimentary skills.
Thanks,