Thanks for the clarification. So are you saying that the ack is really only required for you to know whether to re-send? And so by disabling the re-send parameter, we avoid waiting for the ack at all? This would make sense to me.
I think this is probably the best long-term solution, if multi-threading is not available, this would hopefully be more simultaneous and still allow for the re-send reliability if necessary. Per this link (LAN protocol group support - Developing with LIFX - LIFX Developer Zone) LIFX themselves expect up to 3 failed messages. As a side note, I picked up a Harmony hub this weekend which is able to do LIFX local control and control Harmony-defined LIFX groups with as-good sync as the LIFX app. So, it should be possible (but they may be using multi-threading).
@Townsmcp Appreciate the feedback on your setup. I would obviously prefer the reliability but the popcorning is just annoying enough that I'd be willing to try that until a more robust solution is available like the one Rob describes. I am going to try the code edit tonight (I don't see a new version on github yet so I will follow the guidance in post 231) and will report back with results for groups.