1. d4 d5 2. c4 Nc6
That'd make an awful lot of buttons once more bbcodes are added. Plus, anyone using the chess code is going to need to know the syntax well to use it. Making buttons for it might just make a lot of broken code from people who don't. So I don't think the bbcode toolbar is going to have many (if any) buttons added, requiring knowledge of the advanced bbcode to use them.