This was a fun lesson in many things! Ignore the awful UX.
The Characters, Dice and Dice Faces are resources.
The dice face resources build TWO layered 'texture' via a shader based on values they contain, 1 canvas and 1 spatial.
These material are saved on the resource.
The Die resource can be updated with new faces, and since the Die preview and 'builder' pieces refer to the same Die Resource, they both update (with some signal magic).
