Ability for author to create "Author & Support agents" private comments
Currently, Support Agents can create comments marked as "Author & Support agents" which we use to add extra details to topics that should not be publicly visible (client/sensitive details, configuration, etc.). However there doesn't appear to be a way for the author of a topic to set this visibility on their own comments, they need to request a Support Agent to create a private comment that they can reply to. Please add the ability for authors to create their own private threads.
If user want to create a private thread, he can use "Create a private ticket link"
Is it suitable for you?