Having said that, there is nothing stopping you or anyone else from creating your own user interface having whatever features you want, simply by calling up the BFGminer API. That is why it is there: to allow people to customize their own user interface, monitoring interface, and control interface to the core core engine. And many have already done just that.
Adding 'bells and whistles' that serve very little practical purpose is not what this program is about. This is just a general statement, not meant as a direct comment to your specific question about dual-column display. I've never run more than 16 mining devices on an instance of BFGminer and I've always found its current GUI to be more than adequate.