That’s interesting, I could see where there could be conversion issues between DateTime and ticks, but the actual value shouldn’t be changing if stored as a long. Perhaps you could create a small example project and post to a ticket on Jira? Use the “Create” button.
As for customizing the DefaultSerializer ctor takes two parameters for JsonSerializerSettings; deserialization settings and serialization settings. You can use any of the NewtonSoft features, like overriding the ContractResolver, to change how serialization/deserialization takes place. You then assign a factory method like this to apply the settings:
var config = new ClientConfiguration{
Serializer = ()=>new DefaultSerializer(new JsonSerializerSettings(), new JsonSerializerSettings())
};
-Jeff