James Whitaker updated the Arm Performix Installation Guide in the madeline-underwood/arm-learning-paths repository to expand support for macOS x64 and clarify compatibility with Intel-based Macs. He focused on improving documentation quality by refining Markdown formatting and enhancing technical writing to ensure clear, actionable installation steps. By explicitly documenting supported host platforms and file paths, James reduced ambiguity around platform compatibility, which streamlined onboarding for new users and minimized setup-related support queries. His work demonstrated depth in user support and documentation, addressing cross-platform installation challenges and delivering a more consistent, accessible guide for developers working across different macOS environments.