Instead of creating a “Scan to Third Party Server” service, you can alternatively create a standard, on-device validate or record-only service type with Auto Sync. The result of each scan (valid, invalid, invalid duplicate along with the response text) would be seen by the app user before the receiving server receives the post. However, once each scan hits the receiving server, a DSU response is required to clear the record from the device. The DSU response does not override or change the scan record.
So why is this valuable? Mainly, you can get an “instant” response because there are no LAN or Internet latency delays. Also, the app can work offline.