How would this work if rename is specified?

Good question. This would require a simple restriction preventing patches that use the or-pattern from specifying renames when applied to multiple types. I used PatchType as the foundation for implementing variant patches (via a PatchType::Path variant), so rename is still supported for variants, but not when applied to types.

Similarly, variant patches should not be able to specify derives, so I added a restriction for that as well. Let me know if you would like me to implement something similar.

So the use case here is that you have a bit chunk of the generated types for which you want an additional derive macro applied? Many, but not all?

So the use case here is that you have a bit chunk of the generated types for which you want an additional derive macro applied? Many, but not all?

Yes, some macros (e.g. wasm_bindgen) do not support certain data types, so they would need to be applied via a patch, and it would be useful if this patch were not duplicated.

That is my use case.