The value
HKCU\Software\Microsoft\Windows\CurrentVersion\Privacy → TailoredExperiencesWithDiagnosticDataEnabled (DWORD). 1 = consent; 0 = no personalization from diagnostic data. Per account; restorable by rewriting.
What actually reads it
- Start/lock-screen “suggestions” — tiles and content generated from usage profile;
- Tips popups positioned by telemetry cohorts (per-user within the relavent app);
- Consumer-feature nudge traffic that's served from the account profile — turning it off erases the server-legitimized personality, not necessarily your on-disk activity.
Why privacy presets include it
Ads ID without Tailored-Experiences-off is wiping a window while the door is open — consumer suggestions and personalized content fetch from the same profile pipeline. Consistency check in any tool with a privacy block: the fix should enumerate all four and either justify or ship them together. Refactoring per-toggle decisions each release is how “suggested for you” beams survive users' privacy passes.
ProofTune ProjectEngineering notes — every claim here names the bytes a real tool touches. Verify first, install second.