There is literally zero reason not to add this to the game. All this serves to do is take misclicks out of the equation.

It is absolutely infuriating playing against people who don't give takebacks on obvious misclicks because they are so desperate for any sort of mmr. Its so unbelievably unsportsmanlike, and often the outcome is "misclick basically loses the game", so youre left with, "Should I resign and reward this unsportsmanlike person, or waste my own time basically playing a fruitless game". Often times when this happens, people will just sit out the timer and make the opponent wait for their win because there's literally no better alternative (Which in my opinion, the unsportsmanship player deserves much more than that)

So, add the misclick takeback. If the button is hit within 3 seconds of a move being made, and the opponent has not made a move, the opponent does not need to authorize it. OBVIOUSLY this is different in much more time restricted modes like bullet, but the idea in itself should be used.

EDIT: The utter irony of this entire comment section of just people shouting even more degenerate unsportsmanship just proves how many of these people exist to warrant this kind of mechanical exception. A mechanic that serves to benefit everyone at the cost of a minority of people who don't deserve to be playing anyway receives such a violent declination just shows that those same people congregate here of all places.