Setup up WiFi on a SD card in a Pi3, as per my post a year ago.
Glad I put that down in the posts, forgotten I had documented it, very sad the memory these days.
Seems to work, I get an ip address for wlan0.
Stick same card in a Zero W and a few seconds after booted I get the message
"No wifi devices found!"
Good news is camera is working
Off to Pi forums for clues.
Bela, put notes in the boot partition readme for setting up WiFi/BT/camera when we figure it out.