I was also wondering this a few posts back, but I think this card is meant for the Unifi Wifi AP’s themselves rather than the client devices (a bit confusing indeed).
A question to anyone using this Homey app to block/unblock wifi devices: do you also experience devices looking unblocked but not actually able to conect to wifi?
When looking in the native Unifi Android app (not the Homey Unifi App) the device apears unblocked as well, but it will only actually reconnect to wifi after I block/unblock it once more.