Help! I'm having problem healing GNB mass pull.

[Rilifane]

Feel free to correct me if I'm wrong, but I can't think of an exception to this rule: I believe the difference between "increases healing magic" vs "increases healing actions" is the difference between incoming vs outgoing heals. All of the abilities that only increase GCD heal potency are buffs that apply to the healer, while the ones that universally increase healing are the ones that boost healing on the person healed.

Not that this isn't a weird and arbitrary distinction, but I think that's why those buffs are "allowed" to boost oGCDs. Because the buff can't tell the difference between incoming heal sources, so it just boosts all of them, whereas boosts like Temperance and Dissipation only affect GCDs because they apply to the person casting the heals.

That's indeed how it works but the problem is that nothing in any of the tooltips makes this connection obvious.
And the fact that Fey Illumination applies a buff to all party members for healing done instead of healing received doesn't make it any easier to make this connection. Any of the buffs, like Temperance, Fey Illumination and Dissipation could easily be changed to affect oGCDs by simply applying a double buff to the party that increases healing received.
The problem is still that none of the tooltips make it obvious what is affected and why.

[Semirhage]

That's indeed how it works but the problem is that nothing in any of the tooltips makes this connection obvious.
And the fact that Fey Illumination applies a buff to all party members for healing done instead of healing received doesn't make it any easier to make this connection. Any of the buffs, like Temperance, Fey Illumination and Dissipation could easily be changed to affect oGCDs by simply applying a double buff to the party that increases healing received.
The problem is still that none of the tooltips make it obvious what is affected and why.

Updating healers so their abilities make sense? Why on earth would that ever happen?

[Rilifane]

Updating healers so their abilities make sense? Why on earth would that ever happen?

They'll probably update tooltips from MNK etc. so they make sense and completely forget about the role nobody cares about and that doesn't really exist anyway.
I'm a giant pile of salt.