My idea for reworking:
Healer LB3 full team revive with proper health
Healer LB2 full team revive, but just regular revive (low health and badge so still reduced damage), alive people get full health.
Healer LB1 full team health

The LB2 while doing a team revive suffers from the part that any raid wide damage is generaly still going to cause a wipe since players lack health. Forcing the healers into making sure the healing can be done. This means there is still a significant chance upon people dying (and getting an even bigger nerf in damage). This number of badges is almost guaranteed to cause issues with enrage mechanics, and therefor shouldnt make it too overpowered there.

LB1 is for just regular dungeons, making that a full team revive might be nice there, but conflicts with raids as that would remove the balance there. And just like the tank LB, its generaly not a good sign if the LB is even needed for this to begin with. LB1 idealy is just dps only. And if that cant be done, so be it. For the healer (just like the tank), boosting survivability is as far as you can go here. Adding too much power here would break balance at many other parts (too much power here and it might make potential failing of mechanics a tactic, and that includes deliberate deaths).

LB1 to me is just a treshold for regular dungeons to at least have the button available and get people used to using lbs. While lb2 and 3 are the real important ones.