Yeah, I've had my single-target rotation down pretty good but I've figured out that for groups I'm just wasting time on the Umbral Ice phase - better to just transpose and start a hard cast, by the time Fire 3 is done my mana I can jump straight back into Flares. I thought it would be less efficient because it felt slower but Flare is just ridiculous, two casts of that is worth way more than three casts of Fire 2. Less mana-efficient, for sure, but I figure BLM against mobs is more 'as much damage as fast as possible' more so than mana efficiency. But... all that is probably not super interesting to you as a Summoner! :D

Thanks for all the tips! Definitely looking forward to running some more stuff.