Request: Choose authentication domain

For the security page, instead of either choosing all of the authentification options or just one, we should be able to choose multiple, but not all. All of my users have microsoft accounts and dropbox accounts in the same email name, and I am the only one with google. I would like to be able to have only microsoft and google as the options, because my users keep switching between microsoft and dropbox, even though they are supposed to use microsoft, and when they do that, I am double charged for their account. I just wanted to add this as a feature request. @BJL