I've used the June Tailor basting spray on 2 quilts so far. One had poly batting and one had and 80/20 batting. The poly did not stick as well. Some areas came loose while I was quilting it. Not sure whether it was the poly or not spraying enough. The cotton/poly batting stuck like glue and really stayed together well. I did have some wrinkles in the backing but was able to pull up the fabric and relay it. It still held well after repositioning. I love the basting spray.
I still quilt from the center, just in case something shifts.