My outrigger support is just the ticket for cutting full sheets of plywood in my small shop.
If you own a T-square-style fence, or even one with a round tube, you can build this crosscut support in a few minutes. I milled a 2x4 to fit inside the support tube for my fence. (Use closet pole stock if your fence support is round.) Half-lap joints are strong and easy to build. When you’re done cutting, the support slides and stores up flush against the saw.