Yes this is the one button press PowerOff command that would be used with firmware versions 1.02 and 1.03.
DogDoctor, thanks for the confirmation that everything worked. You shouldn't have to set the PowerOff command to be held down at all. You should just be able to send it the same as any other button press, the Pro unit will take care of the rest. As far as what device you use that is up to you. As you can see it doesn't really matter. I personally still use the Sony PlayStation 3 device, as it has all of the same IR commands as the IR2BT, and Pro unit mapped to it now. The only commands missing in the PlayStation 3 device is the PowerOff command that I have shown you how to add here. The big advantage of using the PlayStation 3 device is that Harmony will give you nice color icons for the X, O, Triangle and Square buttons. These icons are not available for the IR2BT or Pro devices (and Harmony won't let them be added to them).