Machine spoil board questions, your advice please

[EddyCurrent]

I think it's best to make a spoil board the same shape but slightly larger than your work piece. That way, if you have a nice aluminium T slot bed, you can prevent the tool cutting into it and still allow clamping of both the work piece and spoil board with clamps in the T slots. If you use a big sheet of MDF say, you have lost the ability to use clamps on your work piece. Obviously sometimes that's okay if you screw the piece down or use double sided sticky tape.