Use the Custom payload to specify preference settings for apps that use the standard plist format for their preference files.
Add preferences manually
You can use this payload to add specific keys and values to an existing preferences plist file. Not all apps work with managed preferences, and in some cases only specific settings can be managed.
If you’re not sure how to specify a key for an app, change the setting using the app, and then examine its preference file using Xcode to see how the setting is represented.
You can upload a preference plist file directly into the Custom payload but you should remove non-manageable settings using Xcode before importing into the payload. To import the payload, click Upload File and locate the preferences file you want to import.
This payload doesn’t prevent you from setting invalid preference settings, so be sure to test your changes before deploying the profile.
You can add multiple custom settings by clicking the Add button .