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
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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.