Last i checked, nobody had cleared heroic oculus multiboxing yet. But after the change that allowed follow in vehicles, someone might have, but I haven't heard of it yet.

Generally i think you'll want each character to have a premade castsequence with the abilities and targets you want them to use, and have some individual buttons bound to do some things on the spot, like the time stop.
It depends a lot which dragons you decide to use as well.

At least movement isn't the problem for boxing it anymore