Single post in Adding a message to completed trades!

I really like the idea of being able to add a message to a gift or something, because I've been gifted something, and I'd really like to be able to hit a button on the trade that says, I dunno, "accept with thanks" which could be a small popup like a nice? I do understand that you can just PM someone to say thank you, but I am aware that some people are uncomfortable with PMs. As for declining trades, there is an option to leave a message already. :)