Unfortunately I have not made any progress. In the end I tried to add the enabling/disabling of the OfonoContextConnection, like the MouseArea does in the ofonotest code. But the status remains "offline".

Also the broadcast status seems to remain "disabled".

Feel free to try for yourself: https://github.com/cow-n-berg/harbour-broadcasted

P.S. After an hour of testing several times, suddenly the screenshot shows "enabled", but... I don't get it. It does not react to the buttons, it seems.