Azure Cosmos Spring Partial Update Document Id and _etag

I’m working with the patch feature with Spring Data Cosmos (Java Spring Boot). I have a scenario where I need to patch a field in a deeply nested object within my main document class, User.

Suppose that I need to update a flag within User at the path myParentField.flagImPatching. However, the application I'm working on does not have access to the full User document or model; it only has access to the MyParent class (the type of the myParentField field within User). Here’s an outline of the models:

public class User {
	@Id
    private String userId;

	@Version
	private String _etag;

    private int count;

    @PartitionKey
	private String somePartitionKeyValue;

	private MyParent myParentField;

    private SomeOtherParent otherParent;

    private AnotherParent anotherParent;

    // has other fields too...
}


public class MyParent {
	private boolean flagImPatching;
}

In my patch operation, I’d like to update flagImPatching within MyParent using the CosmosPatchOperations functionality.

Questions:

1. Can I pass PartialUser.class to Repository.save() like this instead of User.class (and instead of a UserRepository) when applying the patch operation? Given that myParentField is a child-object within User, would this still correctly update the User document in Cosmos DB? Even if my repository only knows about PartialUser?
2. Regarding the patch operation: The User model includes an @Id for the document ID and a @Version annotated field for the _etag (for optimistic concurrency). Do I need to supply these fields when performing the patch operation with CosmosPatchOperations, even if I’m only updating a specific nested field? I've shown that below.

Here’s how I’m considering the operation, even though I don’t have access to the full User object (taken from an example here: https://github.com/Azure/azure-sdk-for-java/pull/32630):

@Repository
public interface PartialUserRepository extends CosmosRepository<PartialUser, String> { }


...


public class PartialUser {
	@Id
	private String userId;

	@Version
	private String _etag;

	private MyParent myParentField; 
}


...


CosmosPatchOperations patchOperations = CosmosPatchOperations
	.create()
	.replace("/myParentField/flagImPatching", true);

// Assuming I have the necessary identifiers (userId and partition key)
// but I only have access to MyParent class, not the full User (so I've just stuck it inside a container PartialUser)
PartialUser patchedPartialUser = partialUserRepository.save(userId, new PartitionKey(partitionKeyValue), PartialUser.class, patchOperations);