SimpleMDM supports scenarios where more than one device object may exist for a given serial number. Additionally, device objects do not always have serial numbers attached to them. For instance, a new device record may be created before device enrollment occurs. Such being the case, a serial number cannot function as a unique ID.

Nonetheless, the Device – List All API endpoint has been expanded to support searching for devices based on serial number, UDID, phone number, and name. This allows for more efficient device ID lookups. More information is available here: https://simplemdm.com/docs/api/#list-all39