Firstly, the Traxxas 2085x servo is a high-torque, high-voltage servo that is designed to run on up to 8.4 volts. While it is possible to run it at a lower voltage, doing so can result in reduced performance and potentially damage the servo. In your case, the HobbyWing Max 6 speed controller is capable of delivering up to 7.4 volts to the servo, which falls below the recommended voltage range.

However, there is a way to run the 2085x servo at the lower voltage safely. You can use a voltage regulator, such as the Castle Creations 10A BEC, to reduce the voltage output from the speed controller to the servo. This will ensure that the servo receives the correct voltage it needs to operate safely and effectively. Just be sure to follow the manufacturer's instructions when installing and using the voltage regulator.