Currently, AFAICT, there is no way to enable BsonGenerator specific Features.

In JacksonEncoder, the BsonGenerator is hard coded:

    private int writeObject(OutputBuffer buf, T object) {
        OutputBufferOutputStream stream = new OutputBufferOutputStream(buf);
        BsonGenerator generator = new DBEncoderBsonGenerator(
                JsonGenerator.Feature.collectDefaults(), stream);
        try {
            objectMapper.writerWithView(view).writeValue(generator, object);

It'd be nice if JacksonMongoCollection allowed injecting a BsonGenerator implementation (and then passed that to JacksonCodecRegistry, which could then pass that to JacksonEncoder) or a at least set of BsonGenerator.Features which was passed along in a similar chain.