I have to cut a 30" circle from glued up boards. I plan to use a circle cutting jig with my router. My question is which technique is better: 1. Use a 1/2" upcut solid carbide spiral bit and take progressively light cuts until the circle is completely cut through; or 2. Use a jigjaw to remove excess wood close to the edge and then use a flush cutting bit to bring the circle to the desired size? I am somewhat concerned about chipout. Any advice would be appreciated.