change.stream.full.document, change.stream.full.document.before.change are examples of such properties, there may be more. It's crucial to refactor them to be case-insensitive in a forward-compatible way, i.e., if the com.mongodb.client.model.changestream.FullDocument enum gets a new instance, the code in the Kafka connector must not need a change to support that new value. This enum is special because its string values are not equal to the enum labels.

I filed this improvement at the request of robert.walters@mongodb.com.