I seriously doubt it is Vasseur wanting a stiffer chassis. Ferrari has a design board within the team that decides these things and instructs the engineers to set the car up accordingly for each race weekend. This board are the people within Ferrari who are offended by Hamilton's improvement document. They are the people that Elkann is supporting with his last rant. They are the very people who would make any change of management irrelevant. The outcome would be the same.

