TL;DR, There's a video at the bottom of this of me performing my new rotation. A DPS meter is included, though it parses dots a decent amount lower than what the actual damage value is in-game. So the meter is a bit lower than what is actually being dealt.
So I decided I'd share, for better or worse, a new opener I've been using recently on my summoner. This opener on it's own is slightly better than the previous Bio II > Miasma > Bio > Fester > etc. etc. that everyone has grown accustomed to, but really shines once you throw in a Battle Voiced Foe Requiem commonly used at the start of pulls.
First off, for those of you that may not know, it's important to note that SMN dots snapshot Foe Requiem just like Raging Strikes. This means you can re-dot right before Foe Requiem falls off and get the Foe Requiem benefit for the entire duration of those dots. That's a different topic though.
So that said, here's the rotation I now use and list of changes compared to the standard opener, as well as my reasoning behind the changes - along with a video:
Raging Strikes > Bio >(optional X-pot) >Bio II > Miasma > Miasma II (Fester) (SwiftCast) > Shadowflare (Rouse) > Ruin II (Spur) > Bio (optional Poison Pot)(start spamming Contagion) > Ruin II* (Fester) > Ruin II (Enkindle**) > Ruin II (Enkindle**) ... continue as normal.
Note: The X-pot MUST be used at that exact location if you wish to use one. This let's you get all your dots X-potted. It wears off almost immediately after re-applying the 2nd Bio.
* Your latency, as well as how fluid you are with your off-GCD's earlier in the rotation, will determine whether or not you can fit in this Ruin II and still get your 2nd Fester buffed by RS. Under most circumstances you should be able to fit it in.
** Enkindle is mentioned twice, because it will go off in either of these locations. Sometimes the first one fails to go off due to Garuda being animation locked still from Contagion.
The core changes:
Bio gets used twice in the opener, both benefiting from Raging Strikes and Foe Requiem. The 2nd Bio benefits from a Poison Pot as well if you chose to use one. The first runs almost its entire duration out before being re-applied, so it's not wasted.
The reasoning:
Bio is short enough to run almost (you may miss 1 tick) its entire duration inside of raging strikes if used first, and there is enough time for it to get reapplied right before Raging Strikes (And X-Pot) falls off. The rest of the rotation just adjusts to this to allow the Contagion of all dots still, as well as a Poison Pot. This is significant when taking into account Foe Requiem, especially a Battle Voiced one that Snapshots dots. Normally your Contagion'd Bio falls off just after Battle Voice wears off, so your 2nd Bio is applied under no buffs. The new rotation allows the 2nd application as well as extension of Bio under all buffs. (X-Pot, RS, B-Voice Foe Req)
Contagion being used later is the only significant con, and it doesn't change the timers of the dots, or the dps, at all. The only effect is your Contagion has its CD come up slightly later. For me this is a non-issue since I swap to Ifrit after the 2nd Contagion anyways on most encounters, and in most cases it won't make any difference regardless. This would be something to judge for yourself based off your own timings on specific fights if you use Garuda for the entire duration of the encounters.
For reference:
Old rotation - 33 seconds of RS+X-pot Bio (B-voiced)
This rotation - 48-51 seconds of RS Bio (33 of which is X-potted, all of which is Bvoiced)
The amount that's X-potted stays the same, but you gain an extra 15-18 seconds worth of RS+Bvoiced Bio thanks to snapshotting.
Here's a video of it being performed. The meter parses dots quite a bit lower than their actual number, so the overall DPS is slightly lower than what you are actually putting out.(If using ACT in it's current patch as of this posting) I also show my gear at the start. I apologize for blurriness, set it to 720p at the start and it should be readable. DPS peaks 40-45 seconds into the opener at 560.(Parsed, actual numbers are a bit higher) This was self-buffed, no party, no Foe Requiem. The opener when in a party with Foe Requiem pushes 750-800 DPS at times.
NOTE: An extra Ruin II should be fitted in before using the 2nd fester. Something felt off here after I very slightly delayed my Shadowflare, so I just waited to Fester to make sure I hit it with RS still up.
https://www.youtube.com/watch?v=vKXIQk-NKZs