DHCP options can be use to automatically direct devices to your On-Premises cnMaestro instance.
WiFi device types can be pre-provisioned via the Claim Device button in the onboarding screen and also Auto-Provisioned via Shared Settings (gear icon on left) -> Auto-Provisioning. Auto-Provisioning is only available for On-Premises. Unfortunately these are currently WiFi-only feature and do not support ePMP or PMP device types. There is an Approve All button on the onboarding page if you don't want to specify onboarding options for specific devices and just get to managing the device.