Feedback left indicator

Hello,
I have an idea for the site based on a slight problem that arises for me from time to time. Would it be possible to include a column in the completed trades section that indicates whether or not you've left feedback for your trade partner? I'm generally pretty diligent about leaving feedback for people I trade with, as feedback is what makes trust between people who've never met a bit easier. In fact, when I receive cards first I always ask my trade partner to "send me a message when you receive yours so I don't forget to leave you feedback." However, this doesn't always happen and sometimes I miss one on accident. I've gotten messages 2-3 weeks later asking that I leave feedback. Lately, I've just been clicking on all my recent trades to double check, but that gets to be a pain when a lot come through at once.

So, if possible, an added column with the heading "Feedback Left" or something of that nature, and a check mark for when feedback is left would be great. I'd like to see if other people think this would be a good idea as well.

Thanks in advance for reading.