I don't know that there is a "stock" answer to this one. You will need to remain within the capability of the E682 controller--it is good for 7 universes running in multicast and 12 universes in unicast. There might be limitations on how many pixels each of the outputs (e.g., 1-1, 1-2 etc etc) can drive, but I didn't see anything about that in the Sandevices manual--it would make sense that each output would be limited in the number of pixels it can drive, since there are limits on the total number of universes the controller can drive. This might be a good question for Jim St. John. I believe he monitors doityourselfchristmas pretty regularly. I hope this helps.