Earlier quoted context omitted.
Presumably the number of faces in the training set far exceeds the number of dice by more than a few orders of magnitude.
In one of the other posts I noticed this option: > GFPGAN Face Correction: Automatically correct distorted faces with a built-in GFPGAN option, fixes them in less than half a second So apparently there is still an issue with faces.
Example image directly from Stable Diffusion:
https://i.imgur.com/XSk8fIv.png
And here is that image run through GFPGAN:
https://i.imgur.com/I53AGmh.png
Interesting to note how specialised GFPGAN is, as some of the other details (flowers, hair) seem to be worse in the processed image. I plan to finish this image by manually blending the best of both pictures.