I wish it were that simple :).

A workflow is not just externally stored data with a well-defined schema. It is the computation's whole state, including threads blocked on API calls and local variables on the stack. So it is not possible to define translations between different versions the way Edit Lenses do.

So a process checkpoint? They make me anxious.

Why not assuming that you can roll it back to any previous state any time later? Temporal supports such rollbacks.