Can auto-numbering for records be disabled for a project in Redcap so I can add a custom or study specific ID?

This setting can be disabled for development or production projects when the first instrument of your project is not enabled as a survey. If the first instrument in your project is a survey, Auto Numbering is mandatory. To disable auto-numbering for records go to Project Setup and select Disable next to Auto-numbering for records. If you are in production mode, you will need to submit a ticket to REDCap support to have an administrator enable or disable.