If this was added, then what about a addition of /pmlog (Player) to sort through the logs for the certain player logs?
Why would you use / if you can use @? @player starts a convo, @player [msg] sends a single message and @@[msg] replies to a pm. Much quicker and less keystrokes. I'm indiferent to the suggestion, I'm sure it would benefit a few, but I wouldn't use it personally.