Our editors can't see any private comments added to articles when the article is sent to them for the editing process. The comments only do show up on the articles when the editors press on the "Send for review" button. The "Reviewer" is able to read the comments when the article is on their review list.

Also there is an indicator on the article name box on the left pane (The article list for the selected group of articles) stating that there is a comment in the article but this comment can't be seen by the "Reviewer" when they send the article back to the editor. They can only read the comment when the article is in the "review" state. The same goes for the editor. They can see on the left pane that there is a comment in the article but they can only read it when the article is in the "review" state.

This means that the article comments are useless when they are utilized for internal communication purposes during the article "Edit/Review" process.