FWIW, I’ve gone through several iterations of waste boards, job holding techniques over the past couple of years. This is my current setup. Sorry it’s kinda messy but I actually use my machine, a lot
The machine itself sits on an oversized mdf base that is screwed to torsion box. It has a t-track outside the machine frame in front, parallel to X, to accommodate oversized pieces. The secondary wasteboard is currently comprised of five pieces separated by 4 t-channels. The “precision” wasteboard sits on top of the secondary wasteboard, it has been face milled and dowel holes cut to provide the ability to easily and accurately align jobs with the x and y axis’.
In future I will eventually replace the left and right sides of the secondary with four pieces separated by t-track. I may also cut another 30 inch wide “Precision” section if the need arises. Obviously the “precision” section can be easily removed to enable an increase in Z. Having the waste board in pieces like this makes cutting seas of holes less tedious and enables replacing only the damaged sections rather then the whole entire waste board.
This is all over kill for most users but it’s what I like, flexibility.