I've added a custom field to the system table User-Settings called EmailOptIn. It is a boolean field using a radio list to select yes or no. I would like this to default to true for all users, but when I checked "Default value" and added it, I see it as no for existing users. How can I make sure this gets set to true for existing and new users.

Note: I know I could work around this by making the field "EmailOptOUT", but that's not the way I want the field to be. I also know I could run a SQL query to set this field to true for all users once I add it. That feels like a hack and I feel like I should be able to do it through the CMS interface.