[Squirrelloid]

I routinely use reverse communions in MP games. My communions *never* go off script, with the sole exception of battles where the opponent isn't strong enough to trigger gem use (then the boosts don't get cast and so they can't follow their script).

The key thing to keep in mind here is that the second round of casting is wasted - assuming your masters have to cast communion master manually. The slaves haven't gotten their buffs yet, and so are still operating at native levels.

So i often script:
Comm Slave, hold, x3, Spells

The alternative is to give each master a master matrix, that way they can cast the buff spell on the first round of casting (after all teh slaves have cast comm slave), and the slaves can be productive immediately.