Deterministic boundaries appear to be best solved with sandboxes/microVMs/remote infra and unique identities with probabilistic guardrails on top. The old deterministic allow/deny list running on bare metal didn't meaningfully solve the problem of giving Claude determinism. Humans got approval fatigue, and eventually, Claude got access to something like 'python3 FILE.py' and Claude could go to the races by updating 'FILE.py'.