Sorry, I wrote this response as a draft weeks ago but I accidentally never posted it.
Sounds great! My grid is 6mm tall but it was machined from solid plastic, not laser cut. I couldn’t find a material that would laser cut at that thickness. I recommend trying to laser cut thick black paper into 30 small sheets that you can crisscross to achieve the same effect. It worked for my prototypes. You can also use a delrin plastic or something more substantial.