I moved your post to the “Servo controllers and servos” section of the forum since it seemed more appropriate.
The Meastro does not have any built-in support for directly controlling the power rail that the servo is connected to, but you could try disabling that channel in the “Status” tab of the Maestro Control Center by unchecking the “Enabled” box. Some servos will continue holding their position after they stop receiving signals, but others will stop, so it’s worth a try. If that works for your servo, you should be able to write a script that sends a
servo command to that channel with a target of 0 if it has not moved after some desired amount of time. If you try writing that script and run into problems, you can post what you have so far and I’d be glad to take a look.