When you export a lesson or course to PDF, you can include reviewer comments in the document alongside the content. They print in a rail beside each page, numbered against the tile they were left on, with longer threads continuing on a sheet directly after their page.
Filter the export to show only unresolved comments, or restrict it to a single language when a course has been translated. Reviewers get a portable copy of the discussion attached to the material, without leaving Mindsmith to compile it by hand.