Hi, thanks for the info.
I get the idea but it's hard for me to even try to implement at the moment. I haven't done any OpenID related coding yet, plus one of my apps is a Wordpress site and I would need to dab into the OpenID plugin's code. I'm keeping the info though as I may try to go for it down the road.
By the way, it is my understanding that Keycloak has this feature built in. I don't have any hands on experience so I can't be certain on how it works. You may want to have a look at it though in case it's something you wish to integrate in the future.
Thanks again for your time.