Well that's a completely new theory. I don't see how the duration of Suen's charge could affect the comet spawn timer since Lu'lin spawns the comet, not Suen.
It's not a "completely new theory" in the slightest. It's been well-known for quite a while that Suen's charge is what delays the casting of the second comet.
Lu'lin may be a part of the animation for the comets creation, but Suen is the one initiating it. The post you quoted isn't the first time someone has said that the charge is what causes the delay and is, in fact, correct. If Suen charges too far, the second comet will be delayed until after the Inferno. If everyone is close to Suen when the charge goes out, you will always get the 2nd comet. That's all there is to it.
Think about it from a game-design perspective: If the Ice Comet cooldown were attached to Lu'lin and not Suen, the following would be a regular occurrence: Lu'lin casts Ice Comet on player 1 immediately before Suen casts Light of Day on player one. Ice Comet is destroyed immediately without any chance of the player running away. Or, perhaps even worse, everyone is stacked up behind the previous Comet for Inferno when Lu'lin casts a second comet, knocking people out of the shadow, dealing high damage, and instantly wiping the raid.
Long story short: Suen is the one spawning the comet. If you want further proof of this, then pay attention when Ice Comet and Dusk phase line up. You'll see Lu'lin dropping an Ice Comet on a player while also standing in the middle of the room.
edit: And before anyone brings up the fact that there will be no Ice Comet if you kill Lu'lin in phase 1, I'm going to point out that Lu'lin being alive is a requirement for Suen to trigger that ability. I will also point out that Ice Comet in phase 3 is obviously an identical, yet different mechanic.
Hello again, 2nd day of attempt we killed twins and I thought I would come back to share the order of celestials that we used.
Phase 1 - Serpent used 1:30 before Phase 2
Phase 2 - Cranes immediately
Phase 2 - after 1st nuclear inferno = tiger to reduce stacks of blazing radiance
Phase 2 - Ox as Raid CD
Phase 3 - Tiger first to help stabilize
Phase 3 - Ox to help stabilize
Phase 3 or 4 - Cranes again
we have two priest hymns and a shammy mana tide, didn't find the need to draw dragon again as were seriously pushing DPS to make sure we didn't hit enrage. First attempt all 10 lived at the end is when we got it with time to spare.
Hope this helps someone, I know there are different methods out there, this worked great for us, our comp very similar to yours OP.
Tank Pally, Tank Bear
Disc, Resto Sham, Mistweaver healers
mage lock spriest (enhance or rogue) warrior
Hello, resto shaman and TC drawer. We actually 3 heal this fight (as with most fights), but I draw in phases 2 and 3, so I don't do much healing outside of the specials. Here's how I do the drawings:
Enter Chi-Ji when ~20-25 seconds before Day phase, and complete drawing right when day phase starts.
Enter Xuen when ~20s before nuclear inferno. Finish drawing when 5s before it.
Repeat this with Yu'lon and Niuzao, in that order.
Draw Xuen as soon as P3 start. Finish when Tidal force starts (otherwise, the buff will fade before tidal force ends).
Draw Yu'lon ~20s before Nuclear inferno, finishing 5s before.
Draw Niuzao ~20 before 2nd tidal force, finish when TF starts.
Draw Chi-ji (chi-ji can help a lot in P3, but there's no time to do it between specials)
If you're on track for DPS, Suen should be dead before the 2nd nuclear inferno.