If you need to square up the quilt and that means that you cut the quilting threads, I have done so. The binding will be sewed over the cut edge so it prevents the ends from unraveling. You can also draw a chalk line all around your quilt on the square up cutting line. Go in about 1/8 and straight stitch the whole edge before cutting the edge. The 1/8 stitching line will go under the 1/4 binding seam allowance.