"Whisper" to user group within post. Private BB Code with user group permissions.

[geeksquad]

I need something that allows premium users to post content within a post that is only accessible to other premium users. For instance I create a post with two paragraphs, the first paragraph as normal text/content, then the second paragraph wrapped in private tags. While anyone can see the first paragraph, the second paragraph is only visible to premium users who have permission to view the private content.


https://xenforo.com/community/resources/th-user-group-bb-codes.3621/

I have found this add-on and I think it can do what I need but it is "unmaintained"and I don't know if it would be safe to install. @ThemeHouse

Any ideas?