Customers want the ability to manage their devices via cli in Mist.

Unfortunately, neither the customer nor JTAC has the ability to enable this feature. This is something we would like to see for all customers and have been asking for it to be developed. The SE or account team has a process they can follow to get you access if it's still being allowed. I would encourage you to have the SE file a Feature Enhancement Request (FER) on your behalf to make this a default feature in the code.