This kind of roadblock is exactly why many organisations prefer something called a Mobile Device Management (MDM) Solution. Instead of relying on StageNow or custom scripts, an MDM gives direct visibility into serial numbers, IMEI, and other identifiers across ethe ntire fleet. It not only saves time but also sets a bar as to how these values are pulled and stored, which are critical when you are scaling and testing beyond few units. There are some really MDM solutions in the market like Scalefusion or SOTI.