What are you saying is Kodak D76 and what is D76 standard recipe ?
Commercial D76 is somewhere between D76 and D76d with some Boric acid alongside the Borax, but with greater buffering than the original published D76 formula. I guess that's what you're saying. The buffering is also slightly higher with commercial ID-11.
D76 wasn't designed for dilution but that's become a common practice since WWII days, so maybe the increased buffering is designed to help with stability of pH when diluted.