Many thanks for your suggestion, obviously your solution relies in renaming "Power Off" to "Power Toggle" something I never considered.
I had tried a few things but in the end my workaround was to create my own Device and train all the harmony buttons based on old remote I had, the solution works but notice it's a bit sluggish at times, this was the only way I could program my Harmony Activities to turn on/off devices independently.
I'm looking forward to going back to the preconfigured Flirc configuration you have suggested, I will post back after testing your solution, but it looks logical.
Thanks for taking the time and effort in posting your solution.