>But if they are momentarily connected to different networks (frequencies), even though they have the same SSID and same password, Apple software will see them (correctly) as on two different networks so the password will not be shared even when the password is the same on both networks.
I don't get it, how is this an issue? If both devices are already connected to the same SSID, then both devices already have the password. Why would you need to share passwords?
One is connected and logged on. The other sees the same-named network and is not logged on yet because it doesn't know the password. Two different senses of "connected."
Multiple non-unique SSIDs (name) can exist within a single router. More extremely, you and your neighbor can have the same SSID on two different routers.
I don't get it, how is this an issue? If both devices are already connected to the same SSID, then both devices already have the password. Why would you need to share passwords?