Brilliant breakdown on howSierra's simulation framework sidesteps the determinism trap. The 5-15x repetition pattern with multi-agent eval is kinda what separates real agent testing from theatre, especialy when voice channels add accent drift and background noise variability. What's underrated here is wiring thsoe sims directly into CI/CD so latency regressions or tool misrouting get flagged before prod rather than after customer complaints.