I have done what you are describing. I did it so the very top showed the quilt better, it also worked well for the spare bed I have that the foot board it afixed to the mattress making it impossible to tuck in the quilt at the footboard.
Sometimes I regret that I did this as the quilt has limited uses... if I had to do it over .. I would put a narrower border on one side rather than none, leaving some border to have the appearance that it continues on. The binding ending at the quilt pattern and without a "border" of some width was just too "abrubt " of a stop of the overall design.