It's fine to redline once the motor and fluids are warmed up properly. BMW thrashes these cars during development and product testing, including a trip to the Nürburgring. I do it perhaps once a week for kicks and whenever needed in critical situations. Sure, it probably isn't great for the automatic gearbox, but that's bound to fail anyways so might as well enjoy the car now

Plus, its nice to hear the motor and relish the sound!