When you click [Ctrl+Enter] in Rich Text Editor it inserts a paragraph (<p>) at the cursor, and also encapsulates the content before the cursor in another paragraph.

I've already created a custom Rich Text Editor profile in core://sitecore/system/Settings/Html Editor Profiles/Rich Text Custom

which includes a custom Configuration Type which inherits from the default settings, but have set linebreaks to use <br>:

public class CustomEditor : Sitecore.Shell.Controls.RichTextEditor.EditorConfiguration
{
    protected override void SetupEditor()
    {
        base.SetupEditor();

        Editor.NewLineMode = EditorNewLineModes.Br;
    }
}

Even with this setting, pressing [Ctrl+Enter] in the editor inserts a new paragraph.

I though maybe the Editor.EnableFilter(EditorFilters.FixEnclosingP); filter might have something to do with it, but enabling/disabling this has no effect.

So, how can I prevent Rich Text Editor from inserting paragraphs when pressing [Ctrl+Enter] on the keyboard?