Custom converter not used

I mean as an alternative you can override the default Serializer factory and provide the parameters in the ctor:

var config = new ClientConfiguration();
config.Serializer = ()=>
{
    var serializerSettings = new SerializationSettings(); //customize as needed
    var deserializerSettings = new SerializationSettings(); //customize as needed

    return new DefaultSerializer(serializerSettings , deserializerSettings);
}

var cluster = new Cluster(config);

That should give you the same effect.

-Jeff