I'm gradually moving to a new email address, so I tried to add it as a new login using the "add more logins..." button:
That took me to this form:
I filled in the new email.
But when I try login in with that email, it takes me to a new profile. (with the same name as my current one). This is not the behaviour I expected. I expected "another login option" not "create a new profile". This is problematic since I would like to be able to log in with my new email, and also since the new profile doesn't come with moderator privileges.