Is there any interop between v3 and v4 schemas themselves? We have an enormous graph of hundreds (if not thousands) of Zod schemas, many inheriting or extending others. It's difficult to envisage us being able to do an incremental upgrade unless both versions can interact neatly.

But I am looking forward to seeing if this fixes our issue where in the worst case a 500 line schema file turns into 800,000 lines of generated types.