I just realized that maybe I have a hint that could help machine quilters who struggle with the size of a twin quilt or larger. I put my ironing board to the left of my machine, perpendicular to my machine, and I use it to support the weight of my quilt while I am sewing.
I just finished quilting a twin sized quilt and will sew the binding on tomorrow. The ironing board is just the right height and size to help me control the quilt and gravity doesn't win.
This is probably common knowledge....but just in case it helps someone... It took me a few quilts to figure this out, but it sure makes the quilting process easier for me.