The new method of adding interests is great (go check it out if you haven't seen it). However, it is easy to lose track of which column I'm adding to if I happen to tab away for a few seconds, or when I take some amount of time considering things between adding each interest.
Since the buttons are effectively acting as radio buttons, could they also be styled to show their current state? Say, greyed out and darker (or lighter in a dark skin), or given an inverted colouring style, or a radio button-style indicator?
It does say at the top "currently adding to yes. click another header to change.", and that should probably stay there, but it is not where my eyes are going to look for this information (because I don't recall it's there at the time).