It would be nice if a customer's Device Key was listed on the Customer Accounts page on a MSP plan. As far as I can tell, the only way to find the Device Key for a particular customer is to click on the specific Customer from the Customer Health View from the MSP dashboard. Then click to add a monitor, then click to "Add Server Monitor".
I'm currently installing the agent for new customers using a powershell script, so I'm not going to the "Add Server Monitor" page each time to download the agent installer. It would be nice to see all my customers' Device Keys in one place.