Seems like overkill. Fabric is fluid medium and the actual quilting process will produce a small amount of "wonkiness" here and there. Stitching the very edges would not allow the quilt to "breathe". I square units and blocks. Once the top is completed, sandwiched and pinned I begin stabilizing by stitching in the ditch each row horizonticaly and then verticaly. Then, I mark and quilt the entire quilt except for the borders. At this point, I square each corner of the quilt. I quilt the borders. I add binding according to the measurement through the center vertical and horizontal. This is about as square as a quilt can get.