Sparky,
That must be it. Thanks!
I guess that means a wall sconce or entrance light weighing less than 6 lbs. may be mounted on a single gang device box. Could it actually be argued that a 3 hub WP coverplate on a single gang WP box is "designed for the purpose"? It still relies on the 2 #6 screws. A round box with the #8s is a safer bet, but I'll use the hubs on the box to be sure.
