1. It's a provider concern and a developer concern. If your infra is serving broken proofs that might be justification for compensation for breaking SLA.

2. Models only change weekly for closed frontier models and even then they should be reporting model "sub-versions" if only for observability purposes.

3. This doesn't really hold true. Kimi and DS release their models on a monthly or bi-weekly cycle and while it's still DS-v4.1-Flash or whatever, under the hood it's DS-v4.1-Flash-1017 or some other date code identifier of which specific model it is and that is both exposed to the user and that model version can be requested explicitly by the user.