There is reasonable discussion being had about the merits of using Chi Explosion on all fights, including single target. Although there is much more testing that is needed, there are some very good examples of people who are very successful with this, such as Raitank (Kazzak-EU)
I am not ready to start advocating for everyone to switch as there is much we don’t know or haven’t been able to hammer down yet, but people are working on it. In the least, it requires t18 4pc and the Sacred Draenic Incense from Archimonde, so if you don’t have both of those, then stick with Serenity for single target and CX for multi-target.
Much of the reasoning for why this change may be beneficial can be found here:
As usual, I will update any with any information as I get it. I’ll also (hopefully) finish the survival guide for HFC and begin the maximizing guide, but this Chi Explosion discussion has been taking center stage.