Renaud Vandegar expanded the achievement criteria for The Underkeep Stories in the zarillion/handynotes-plugins repository, introducing a new Third Party Operation condition to broaden completion requirements. Using Lua scripting and game development expertise, Renaud implemented this feature as a focused, traceable change that preserved existing user progress while enhancing the scalability of achievement tracking. The update was linked to a specific pull request and issue, ensuring clear documentation and maintainability. By refining the logic for achievement completion, Renaud enabled richer gamification coverage, laying the groundwork for future expansions and supporting higher user engagement without introducing regressions or additional bugs.