My WordPress site currently displays users' identifying information by their FIRSTNAME + LASTNAME.
The vast majority prefer to be known by their usernames. I've instructed how to change their "Display Name Publicly As" manually (i.e. via their User settings) but this is less than ideal.
I would like new users to be shown by their usernames as the default. Note that I want this to reflect in several plugins that refer to the "Display Name Publicly As" property.
How can this be done?