I came across another interesting one last night, when queued for a Duty Finder CT (me on my SCH, queued with a WAR friend)

On the "Corridor" fight; We were on Party C and Party B wiped twice in a row.
On the next attempt, my Warrior friend joined party B to help out; so I sent Eos in with him.

It turns out that the corridors are close enough together that you can place a fairy in the next corridor and manually tell it to spam heals on the other alliance party's members - it'll be outside of "Rouse" range but not out of range for you to issue ability commands. Since with the latest patch you can now tell your fairy to cast Embrace on non-party members, this means that technically a really good SCH can main-heal two corridors at once.

I ended up getting my fairy to main-heal their party (via Embrace spam on their tank who I kept focus-targeted, plus the occasional Whispering Dawn) whilst I main-healed our party (via normal targetting and Physick/Adlo/Lustrate). If I'd been a bit more practised I would've probably gotten away with using Cleric Stance too...