Thanks, that makes it easier. But are you saying I don't need to wait for until Cellular.connecting() == false? In this post from you it says I do.
"When your device is flashing green it tries to connect. So it would be adviasble to first end any of these connection attempts via Cellular.disconnect() and only then when Cellular.connecting() == false call Cellular.off(), but since the module needs some time to comply with the network demands, some blocking behaviour is to be expected."