Thanks LBD.
I wanted the phenolic since everything I have tried is just too flexy, even worse if I add a replaceable insert for the kerf.
The way you made yours is excellent and easily doable, but nothing I can cut with the laser would be stiff enough. My plate is 13mm thick and I have maybe another 3mm I could stack on top and still have it flush.
If/when I notch my new one, intent is to route out a recess about 4mm deep so I can use a variety of materials.
I think I could actually DT the recess with a DT bit, but then the inserts would need to be worked the same versus just a bunch of ripped blanks.