If you do get the "you have already left kudos" message, that's a good time to leave a comment like "Second Kudos ❤️" or "If I could leave kudos again, I would." I remind people & yet there are some works I love where I've been shocked to find I haven't left kudos yet (I don't usually read on AO3).
Laurel KrahnI know I bang this drum a lot but if there are fanworks you love on AO3 be it fanfic, fanvid, podfic, art, or something else, leave comments on them. Definitely leave kudos, but comments mean a lot. Don't have to say a lot—if you love it simply saying "I love this" may make someone's day. ❤️