Plan for your non-DPS people to simply survive until your DPSers can break into their insanity phased instances and help out. I run Healer+4xDPS, and I simply micromanage 1-2 screens of people to kill off their targets while casting self-heals on my healer.

If you use a focus targeting setup (like I do), I just turn off the blacklisted TAB and manually type "/focus player" so that everyone is now their own focus and I can broadcast TAB targeting and DPS abilities. That seems to work OK.

I've heard it's timed as well, maybe you can just wait it out. (Contemplating having all hunters Feign Death and just self-heal on the main.... hmm..)