E9S: I think this is fun to heal for a first floor compared to E5S and E1S. The time between raidwides is not as long as Ramuh which forces you to put more effort into topping up the party; for example, having to heal after Obscure Woods before the knockback and before the Phaser mechanics. The tiles phase is interesting because of the movement restrictions that make it hard to use aoe heals like Earthly Star effectively unless you're in a static and specifically time your star to go off when everyone is in the inner tiles. The damage up buff is a great idea. Statics with skilled healers can choose to let the clouds in; the damage up is significant but not enough to prevent a zero-GCD heal plan. Groups that can't deal with 4 stacks can let in 1-2 instead. It's a cool way to let good healers contribute indirectly to higher DPS on the boss. Of course this wasn't possible during the first few weeks but now that most players in BiS it is doable.

E10S: This fight is boring because like Ramuh the damage is spaced very far apart. Earthly star and random regens can take care of the vast majority of damage in this fight, there is very little reason to plan heals for this. The triple stack damage was interesting especially when undergeared. At BiS, Shadow Warrior became another way for skilled healers to contribute indirectly as overmitigating it allows the group to handle the orbs standing in the middle without having to run to the edge. I think future raids should definitely include mechanics like this and E9S clouds, but I suspect this was not intended by SE.