An example of recently introduced feature is live tick data, which was not available in earlier versions. In older versions only 250msec binned data was available. They are constantly adding and modifying things as their API is constantly evolving.
I do not know if IbPy is working or not, I am not using it. However, the fact that it has not been updated for 2 years is a serious concern.
In the thread you point out, the same question is discussed, however, it seems like Backtrader is not ported to native IB API.