Related to this question (about fixing spelling errors in nominated questions), but about actually answering one or more of the questions.
It seems that this kind of defeats the purpose of a quality review, at least if you do it properly, but I haven't found anything to verify this. Will I mess anything up if I answer open evaluation review posts?
Sometimes, a new answer will put a thread into an entirely different quality level (hopefully better). If this is OK, is it better to post the answer(s) soon after the queues open, or wait until nearer the end?