That scan approach won’t work for hidden SSIDs, but it will handle other SSIDs elegantly and won’t connect to any SSIDs not explicitly configured.

I’m really not sure how phones do it, or how that can be applied to the Espressif ESP-32 wifi libraries. I don’t think they round-robin connect to all configured SSIDs, one after the other - imagine you have dozens of SSIDs (I do); the power consumption would be horrendous. As you mention, maybe an active probe, but I can’t find that in the Espressif API:

I don’t see anything in that API other than the (expensive) connect-to-an-AP in station mode.

I’m not overly worried about this at the moment, as it is relatively simple to switch to a specific SSID in a one-line script triggered by geolocation. Most likely users will be controlling wifi by geolocation / car state anyway. But, if you have time to look into any better way of doing it, please have a go.

Regards, Mark.