We'd like to request an official position on a very small addition to PerformanceTimeline specification. We've added a hasDroppedEntry parameter to PerformanceObserverCallback, which is in https://w3c.github.io/performance-timeline/#the-performanceobserver-interface, and logic for it in https://w3c.github.io/performance-timeline/#queue-the-performanceobserver-task. It lets a developer know when an entry has been dropped from a buffer that the PerformanceObserver cares about. We reached this solution when discussing https://github.com/w3c/performance-timeline/issues/169 in a WebPerf WG call.