There is some support for this. You can configure anything about a site from the dashboard, except individual device parameters that would be tied to the MAC address of the hardware you’re adopting. For example, you can prepare the entire wireless network design without any access points on hand, but you cannot adjust the individual AP settings until it is adopted.
You could potentially adopt the devices on a lab network to prepare them, then use the Move feature to transfer them. I am not exactly certain about how effective this trick is yet.