Regarding Account linking flow, for a person who already has identity associated with an organization, if the same person attaches the same org using Account linking, we are getting duplicated detected error which is correct.
But irrespective of this error, the organization identity is attached again to the person's record. Another issue is that ePPN is showing twice in the identifiers as well. Please see below one of the test records where an org identity is attached irrespective of duplicate detection and the duplication detected error and how ePPN is attached twice.