email_is_missing.mapProfileToUser has no affect on the above as this method is being invoked after the email check fails. One must use a custom getUserInfo method to get around this restriction. See here: https://github.com/better-auth/better-auth/blob/6a0898fa88d1a49163b711fdbfa05489e0301a2c/packages/better-auth/src/plugins/generic-oauth/index.ts#L606mapProfileToUser now works as expected. Still the outstanding issue of handling missing emails