Thompson might be better served working on a little 10-15 foot pull up jumper.
Seems like it would be easier to teach someone to make that shot compared to a 3 point shot. It would also give him options on times he cant get all the way to the rim. Just because he gets the ball behind the 3pt line wide open doesn't mean he has to shoot that. Take two dribbles and stick the 12 footer in their eye. His FT% isn't good so maybe not.