Done it. I am 100% group geared, I haven't been on a raid since Rain of Fear. My guild doesn't even have a cleric main. We have one box cleric and one alt cleric. I'm it as far as main healers. I'm in no way saying its easy and its probably the first mission in a long time where I have to really be on my toes as a main healer. Only doing Icebound Avatar while trying for the All Credit to Rallos achievement last expansion required that level of dedicated healing and then cliffs in the expansion before that. A lot of this requires getting some good HOT going as well as Zrelik's recourse and then rain heals and single target bump heals as needed. Its more work than in recent years but not impossible by any means.