Yes, I have. In fact I received a specific brief because of my particular timezone to comb the overnight posts for duplicate stories and weak / unsuitable memes.

When things get busy, I can end up removing a handful of duplicates every day, although there are fewer these days than there were.

We miss some duplicates because we don't search on every new post and in any case, the search is sometimes inadequate.

I agree it's not rude to occasionally have a repeat message, but is our policy to remove duplicate posts. Only under rare conditions do we deliberately allow or put them there.

Considering it is mod policy and also my specific brief to remove duplicates, I try to remove them as completely and yet as politely as I can.