I think I found an alternate way to set this in the registry. HKLM\SOFTWARE\DELL\UpdateService\Clients\CommandUpdate\Preferences\Settings\Schedule ScheduleMode = ManualUpdates 
With the older versions of Dell Command | Update, I was able to use dcu-cli.exe to import the policy for Command | Update. With Dell Command | Update 3.0 for Windows 10, I can not find a way to import the policy (XML file) using a command line.  Is this still an option? I have a few thousand machines I'd like to push this to and my goal here is to set the client for "Manual Updates Only".  I'm open to setting this another way if anyone has a suggestion.
Dell Command | Update 3.0 - Import policy via command line?