Usually they don't support that.
I am staring at an EFIS, a 430, A TF700 running Anywhere map, an ipaq running mountainscope, a 496 with XM WX, and adding an ipad mini running xavion, and in the soup none of that crap matters.If you are staring at two different tablet devices in the cockpit, wouldn't that sort of impact your ability to see other traffic and terrain and crap like that?