When I went to the dealership Saturday and drove a 13 I was told a tune would void the warranty.
Every dealer and their mother would tell you that. If the service manager ever heard about an employee saying it was O.K....the conversation would be short and very unpleasant!
No dealer EVER wants to tell a customer that, sorry, Ford believes you did something, so the repair is on you. Some managers are better than others at helping customers fix shit, that really, wasn't Ford's fault.