SITD sounds simple for machine quilting but it isn't. If you need to change the direction you are sewing in, you have to rotate the whole quilt. I would SITD on the large star lines to stabilize the sandwich first. By doing long lines diagonally across the quilt and then turn the whole quilt and go the opposite way you should have a minimum of turning. After doing that you could then decide what other quilting you want to add.