Few times while I was writing long posts, suddenly my PC restarted and I had to write whole thing again.
While I was in DP, I think they had some feature which saved what I was typing in 'Quick Reply' box. So, even if something happened and the page closed, I could see the text in the box when reopened that page.
It short, it saved the text (unposted reply) like Wordpress does by drafting.
Please try to put that mod here. I am sure it will help a lot.