2. Suppose that the serving project A is serving some model version 1 and a new model is trained and it starts serving model version 2, but on runtime due to some reason reason we need to revert to model version 1, what would be the best way to achieve the above?

If you archive the model, then the cleaml-session will pick the "latest" non-archived model, essentially reverting to the previous version. Also notice that it supports multiple versions on a single endpoint (again also a feature of Triton that it exposes and manages)