I don't have the book so I don't know what the jig is.
I made my dedicated (specific angle set to perfection and locked down) sleds, to cut segments, from plexaglass/acrylic sheet. I do a lot of simple segmentation. Worked so well I made a sled for 45° cuts. Perfect every time.
It's way thinner than MDF, doesn't chip, totally impervious to water, oil, solvents, etc. and you can get the size you need from pretty much any glass/window repair shop.