After a long time i decided to stop the boost. I let him keep the money even if he could not finish the job. We had a little more then 50% WR and lose a lot of Games in Duo.
He is not a bad Person, and he is also a good Player. But i didnt like the attitute at the end. He makes Teammates tilt by taking their lanes, ignoring their chat, and sometimes just chat all day with the team. Its hard to stay calm, and its even harder to see your booster makes the team tilt and lose the game.