Nicky,
I didn’t know what “Norton White Tile method” is, so I asked Gemini AI. It came up with a detailed description and named you explicitly as the inventor of the method. That’s super cool! I love how practical and low-cost your method is and that it produces such a robust result. You did the world a great service sharing your technique with the rest of us. Thank you! I’m deep in the metal work right now, but your technique is now on my list of things to try. 
The detail you have achieved with 308 DPI on wood is amazing. What resolution do you typically use on the tiles?
My use of titanium is very different from your tile method. I’m alternately anodizing, ablating, anodizing titanium metal sheets to render full-color dithered mosaic images. Here’s a link to an LB post about it, and here’s a link to my GitHub site describing the process. I see you have a MOPA laser. I’m considering buying one laser to see if I can directly oxidize the colored dots for my mosaics, but also so I can try diffraction gratings and see how they look when anodized.