Lone star type quilts are notorious for having fullness. I suspect with the added diamonds in your broken star quilt the problem was amplified (those diamonds, even strip pieced are very tricky to work with). Many end up being close to a B cup in the middle area where all the diamonds come together. Quilting that quilt on a DSM will be a challenge for sure, to quilt out the fullness and not get puckers. If you don't have a rack set up, you may want to consider hand quilting this. Hand quilting will be much more forgiving in working in all that fullness and you could do it big stitch style if you don't want to tackle traditional HQ tiny stitches. Not sure if a high loft batting will help in this case and as Lori S mentioned, they are very difficult to manipulate through a DSM. You not only have the limitation of throat space but also the limits of hopping foot clearance.