The scenario is that when a new device is connected to AP, it would be easy to click to copy MAC Address of the new device in APP/Devices and paste the MAC Address into APP/Settings/WiFi/MAC Filter: Allow-list.
BTW, I must say Alta Labs is making progress in improving Alta Networks APP. It was impossible to turn on/off a certain WiFi in last-version APP; but you can do it now in latest-version APP. Please feel free to try it. Well done, Alta Labs!