Making more functions taking Error ** return bool (commit b6d7e9b66f..a43770df5d) created a number of false positive CHECKED_RETURN Coverity issues. Peter notified me back then. This series could help (we'd have to double-check), but it covers only the getters, not the setters.
Peter, are you still interested in reducing the false positives (as opposed to marking them)? Philippe, are you still pursuing this series?