Would it be a good idea to allow us to edit our questions and answers until someone responds?

I was on another Q&A site that had that policy and it worked out well. I find that sometimes I want to edit something after the 5 minute editing window goes by. It seems to me that this should be permissible provided that, for a question, that there have not been any responses or GQ’s and, for answers, that nobody has added any responses after yours and there were no GAs given for your answer. What do you think?