I think Watching the @moderator inbox would only send you email notifications of the PM versions of flags (eg ‘something else’, or the notify about reviewable item after messages). I don’t believe you get an email notification for non-PM type flags?
I think if you want them immediately you may be able to set up a ‘Reviewable event’ webhook that you can link to something? (though I’m afraid I don’t have any experience with that myself)
