Any idea if the woff2 files served by Google are the same? Or that they maybe are more optimized for web?

I’m afraid I don’t know for sure, I only know that the woff2 file I generated with the CLI worked fine in all the browsers I needed it to. Other posters have said that Google may do some user-agent sniffing or other fingerprinting to maybe serve an even more reliable version, but I can’t comment on that.