GoK NNUE playing against itself! The stored project would be too large for two GoK Chess engine instances. To create the second instance, simply click "See inside", duplicate the "Board" sprite, remove "Template" sprite, and start the project.
Any Scratch chess project can be integrated, it only needs to implement a thin interface. This will allow chess engines to play against each other automatically. Original project: https://scratch.mit.edu/projects/1033757275/