Thanks. I changed to use io.confluent.connect.protobuf.ProtobufConverter and as expected the Kafka consumer now gets a DynamicMessage with the various fields. I was expecting/hoping the timestamp fields would be represented as a google.protobuf.Timestamp object, but instead it was returned as a DynamicMessage with a single field with name google.protobuf.Timestamp.seconds.
Is there some special config required to make this deserialise “properly”? I am using 7.2.1 so I was under the impression this would work based off Post protobuf schema in Schema Registry - #2 by rick.