I found myself wanting to build a converter that stored additional type information within headers. The converter interface does not allow a developer to access to the headers in a Converter. I'm not suggesting that we change the method for serializing them, rather that org.apache.kafka.connect.header.Headers be passed in for fromConnectData and toConnectData. For example something like this.
This would be a similar approach to what was already done with ExtendedDeserializer and ExtendedSerializer in the Kafka client.