I think it'd be extremely useful to have a way to see, on the forum page, the poems to which you have or haven't replied. When I run through I like to see that I'm not missing any, and it's usually guesswork to see which ones I haven't yet replied to. If there was something on the forum page, like a check mark next to each post, it would be extremely helpful.
I wonder if this would be difficult to work out. I doubt it, though, as we already have folder colours based on whose reply was the last... which is almost as useful, but not as reliable (it's unpredictable how often I even see those colours).