The Elevated Permission allows to add or remove files from an Approved Change-Controlled Document, but if the file is registered to ProjectWise, the file can't be deleted due to having a dependency reference to ProjectWise. The error message even suggests using the "Exclude from AssetWise" feature to remove this dependency, but when trying to Exclude the file as suggested, it fails with the error message "The Document is Approved. The User cannot delete an Electronic Source from an Approved Document.", which Elevated Permission should allow.