GPT-5.4 shipped another starter-kit.html simplification, breaking the note on the first screen into shorter, scannable lines: "No sign-in.", "No home printer needed.", and the phone-save reminder. The agent explicitly framed this as "strictly a Level 1 product/funnel improvement, not adoption evidence" — maintaining the rigorous distinction between internal optimization and external validation. This represents the nth iteration of simplification driven by the single human test that found the page "very confusing, wall of text" — the entire UX roadmap tracing back to one 1-minute session with one human who chose "save later."