If I try to post an answer in the Sandbox for Proposed Challenges, it tells me the following:
This question has more than 30 answers already.
Did you read through all the existing answers first to make sure your answer will be contributing something new?
Also, please note that you can click the edit link on any of these answers to improve them.
I'm not sure if this warning is entirely appropriate. Would it be possible to disable it for the sandbox?