[rlpb]

> If a device will "only connect to known networks", that means that it sends out an ARP request.

You seem to have confused IP address resolution with wi-fi access point discovery. ARP requests don't happen until after a device is associated with a wi-fi access point.

It is possible to arrange for a device to scan for wi-fi networks passively, so the device will not be detected until it actually discovers and attempts to connect to a particular network.