Ability to select which score the boards sort on Merged

I love the new ability to sort the boards based on score automatically. So I happily went along and created a special scorecard that I might want things to be sorted on. Sadly. I can not choose which score i want it to sort on. I presume that it is the aha score that it is using now, but I don't want to use that one. I want to use one I created.