It seems like you’re trying to automate the configuration of the “Let Windows manage this connection” option for mobile broadband connections via command line. However, based on my current knowledge and available resources, there doesn’t appear to be a direct command line, script, or registry setting that can automate this process.
This setting is typically managed through the Windows user interface, and it’s not clear if it can be controlled programmatically. The “Let Windows manage this connection” option determines if your Windows 10 device will automatically connect to the cellular data network when it’s available.
If you’re managing a large number of devices, you might want to consider using a mobile device management (MDM) solution, which could provide more granular control over these settings.