Best scenario:Fairs.
I'm just thinking that there must be a magic number of targets where casting FO on cooldown is better than saving it for PC. Perhaps I am missing a vitally important point here, that is very possible.
Okay, I'm not good with coding or maths at all, so bear with me here. I just want to convey an idea, hopefully my sleepy self can make sense of it.
From what I understand, on single target, a lot of value can be added to both Frozen Orb and Prismatic Crystal by delaying Frozen Orb to sync up with PC. This is because FO will do twice as much damage, and - not counting the one free FoF proc - also give twice as many FoF procs. On the other side, you get a lot more value out of PC as you will be able to fire more FoF-ILs into it. Okay, simple enough.
Now, if we increase the amount of targets outside of PC from one to two, it seems to me that the increase both FO and PC gain by lining them up with eachother is dimished by a bit. As you showed above, it's still worth it, but there should in theory be less of a difference on 2 target cleave than single target.
Here's the question for me, at what number of targets does the optimal FO/PC usage change from being based around PC (syncing FO up with PC by delaying FO) to being based around FO (syncing PC up with FO, by delaying PC)?
Perhaps it's a silly question, but I am quite curious about this, as I don't entirely know the optimal way to use these cooldowns when there are intermittent add phases such as on Imperator, and long-lasting multi target cleave such as on Tectus.
00:00 MI+IV+FO+PC (+2min trinket)
01:00 FO
02:00 FO+PC
03:00 MI
03:30 IV+FO+PC (+2min trinket)
04:30 FO
05:00 MI
05:30 FO+PC
06:30 FO
07:00 MI
07:30 IV+FO+PC (+2min trinket)
Of course it depends, I wait until have some FoF&BF before use FO+PC - 2FoF+BF is great, but dont wait on it!
If you know that BL is pop in 30s delay all cds/trinkets (save MI is very important!)
Save FO if you are sure that you have 3 or more targets stacked. For example on Imperator fight use FO every CD (on HC you must save cd on "adds phase") but dont wait on big add - problems with cleve (range).
But in "adds phase" when you dps Warmages, when you dont have PC use FO on SMALL ADDS (tank should tank them in place, you dont kill them asap - dont wipe raid

Worth is save IN on 3+ targets.