This could be helpful when link with the other request I just shared: https://community.disciple.tools/topic/89/link-a-magic-link-template-to-update-needed-triggers
Having multipliers that are not users, you could use magic links that automatically get sent to them when Updates Needed triggers get triggered. Since non-users wouldn't get notifications about those comments, the combination of these two features would allow non-user contacts to be notified about updates needed for contacts they are assigned to - and give them access to make those updates.