As someone said, a seam running perpendicular to the rollers on a LA makes a big bulge on the rollers. Ask me how I know this..... The size of your quilt should fit length or side/side. so that won't be an issue. If the back is extra large and will still fit onthe the machine, I don't mind moving the quilt to one side so a larger piece can be left over. Just need this info up front. Also, If I know the extra is planned for some use, I try to stitch only within the quilt top.