Hi,
A small test scene worked for me, I set the time scale to 0, then apply an iTween move to action, and checking real time one and off truly reflect the time scale value, itween only animates when time scale is 0 if "real time" is checked.
WARNING: when messing with time scale value, don't set that time value on the start state, it won't work. Wait one frame or implement a delay. I don't think it apply in your case, but just a reminder.
bye,
Jean