I did it. Unfortunatelly it didn't workAlso, I’d say probably have location and cellular data (you can test these two settings individually) enabled for the oem app and connect to tello, shut tello, start wifi deuther, start tello and connect to oem app. Then perform you wifi analysis.
Wifi channels 12 and 13 are unreachable for Tello even I previously entered stock OEM Tello app for proper region initialization.
As @volate!lo said, it looks a dead end street.
Forum's guru help needed here to give us any tool for asking/setting Tello region.