yeah.. was thinking the same thing - some kinda FIFO implementation to queue up all these Lightify Scene commands. I do like the way my core Plugin (Dimmer type extension) is working however, as it is pretty responsive to switch/keypad commands from my Insteon devices. Maybe I'll prioritize commands from my Insteon devices higher, and allow just these background 'Light Scene Executions' to lag if needed. Not sure if I'll try to handle send/recv independently though and I may just serialize them from a round-trip perspective.
thanks again for the tip.