LoggingEventVO is never assigning a value to callerDataArray so the caller data is omitted regardless of the value of SocketAppenders includeCallerData property.
As far as I can tell, this should probably be implemented in
LoggingEventVO build(ILoggingEvent le)
ledo.callerData = le.getCallerData();
I'm unsure where the caller data should be obtained, though.
LoggingEventPreSerializationTransformer will probably need an includeCallerData property that's initialized whenever the setIncludeCallerData of SocketAppender is called. It could then execute getCallerData(), if requested, before calling build.