Its definitely worth it - assuming you already have one up on the boss and the big guy, throw your second SEF at whichever you think will live longest every time your current one dies.
I can't say I have trawled logs to prove it, but the other monk in my group insists the pea shooter bombs hit them occasionally too, which is a nice side perk for the raid in theory - I am generally too busy to pay attention, I just recast it whenever my aura says one despawned.
You don't ever want to do flamethrower, its a pretty massive dps loss compared to a hunter or boomkin doing it and sitting almost constantly at high stacks.
In addition to Zen Meditation you can also use your Elusive Brew to avoid whirlwind damage from Phemos. You can dodge and parry the ticks.
https://www.warcraftlogs.com/reports...ability=157944
Sry 4 bad english if present :P
Monks are now a niche class. In my opinion, you and your raid/guild would be best served by you filling your niche and gemming/enchanting/gearing/speccing to fill the role that WW monks are currently designed around. YOUR NICHE IS NOT SINGLE TARGET. Gear for Ascension/Chi Explosion and maximize the fights you're meant to maximize. Do your best in the others. Stop pretending you're kitty cats cause you're not.