Good addition — temperature=0 plus a fixed seed is a useful middle ground, especially for integration tests where you want some real-API coverage but less noise. The caveat you flagged is the right one: seed behaviour isn't guaranteed across model versions, so it's a noise reducer not a flakiness eliminator. Still worth doing. I'd pair it with snapshotting the model version in the test so a version bump is a visible signal rather than a silent source of drift.