I have never need the precision to have to face my spoil board, but if you need it that bit should work. You should probably use my perpendicularity tool to make sure you router is super straight or you will leave stripes in your spoil board. It is pretty easy to use if your tool is leaning a bit a small piec of tape or foil or soda can can shim it in the right direction. This will also let you cut faster.
Reply To: My 5' x 5' build