I've made a laser cut prototype of the board. It's the led diffuser an the top face of the board. I will start to a 91 cells board, due it fits well in a A4 sheet and I could make a single PCB with all the electronics. This will help to develop the software, later it could be escalated to bigger boards with more cells and grouping cells to simpler pcbs interconnected.
This design will be a single board with all the sensors and leds. The microcontroller will have an usb connector to manage it from the raspberry or other system.
I've cut also what will be the interface to the board, a little oled screen and some buttons to select and navigate the boardgame cells. This interface will be connected directly to the Raspberry Zero
I will add later the schematics when are finished.