This addendum extends Smith (2026, DOI: 10.5281/zenodo.20548943) to address a critical fabrication advantage of biologically-derived physical reservoir computing substrates over conventional silicon-based photonic systems: the substrate can be grown rather than manufactured. Spider silk proteins are now producible at commercial scale through genetically engineered silkworms. Lepidoptera wing scale nanostructures are biologically self-assembled with nanometer precision through chitin deposition pathways that are genetically tractable via CRISPR. In contrast, silicon semiconductor fabrication requires perfluorocarbon emissions, ultra-pure water at scale, and generates hazardous waste across its lifecycle. This addendum presents the environmental case and the biological production pathway as a distinct and substantive advantage of the proposed architecture.