Foundation model vendors generate halt evidence that hyperscalers do not.
The Coase Inversion described in Paper 1 surfaced a structural property of agent governance: a non-trivial share of the halt evidence visible in public sources is generated by the vendor wrapper rather than by the institution itself. We test this property at the agent level by comparing halt evidence between agents served through foundation model vendors and agents served through hyperscale infrastructure providers. Under the v13.1.0 substrate, FMV-served agents exhibit halt knowledge in 76.8 percent of cases against 73.8 for hyperscaler-served, and robust halt categories in 7.29 percent against 6.29. The direction confirms the Paper 1 finding; the magnitude is materially smaller than the v11.1 baseline indicated. The implication for cross-institutional propagation persists: when the vendor changes a halt-relevant configuration, the governance posture changes simultaneously across every dependent institution.
Each pair of bars compares the share of agents with the named halt evidence category between those served through foundation model vendors and those served through hyperscale infrastructure providers. FMV-served agents exhibit modestly higher halt evidence on both metrics, approximately 1.16 times the rate observed on hyperscaler-served agents for robust halt categories. The Paper 1 mechanism, that vendor platform wrappers contribute observable governance evidence beyond what the institution itself generates, holds in direction. The magnitude is narrower than the v11.1 baseline suggested. The cross-institutional implication persists: a vendor configuration change propagates a governance change to every dependent institution at the same instant.