You are right, that was a poor choice of words. I changed it.
think you are (partially) right. When I changed the duty cycle form 0.1% to 1% the joining process was faster. However as expected, it still isn't instantaneously. If the node retries to join at a lower data rate, is there anyway to see at which datarate it is trying or at which is successfully joined?
Furthemore changing RX2 window to SF9 or leaving it at SF12 (default) didn't seem to make a difference.
LMIC.dn2Dr = SF9;
btw my code doesn't do anything else then sending, it is pretty much the default example code.