It would especially go counter to our our goal of trying to keep people in the zone with their characters when in the game instead of being constantly distracted by OOC chatter
That's true. And I did ignore that goal when I made the suggestion.
To Bean's point, I don't necessarily agree that migrating OOC communication outside of the game is less risky in regards to developing cliques.
If cliques are going to form, they are going to form regardless of how OOC communication occurs - although, given typical human behavior, I do agree that it is a fair assumption that less people will participate in OOC communication due to the additional hurdle of having to use an outside resource.
When it comes to cliques, cultivating a healthy culture within the game and community that opposes their formation is key - and that said, I recognize that this is exactly the goal you are going for with a change of this sort.
Also, I should have known you have already considered group tells.
Feel free to quote Anakin Skywalker to me, "YoU unDeRestImatE mY PoooOoweeRr!"