I know this is the 562th time someone asks for a cancel button, but come on. Can´t be that hard to do, and it is really useful. (There were some plays in this tournament I really regreted not having one- Even the last turn of finals, I said to my team before opponent moved: Well, gg, just made the worst play possible) And couldn´t go back cuz there is no little friendly button.
Edit: If not, why is that it can´t be done. I can see no harm.