I think it depends on how you plan to use your camper? If you are constantly on the move then the awning sides might be a good idea but if you plan to pitch up for a week or two in the same location then you might find the Airgo Lite very useful to maintain base camp and offer reasonable flexibility while using the MP for days out exploring.
We don’t sleep in the MP when based at the same location for more than a couple of nights, we have a 5m bell tent and set up home there. The MP gets used when we are out for the night exploring or gigging or cycling , I don’t see the benefits in complicating the interface with driving, sleeping and camping by extending the vehicle enclosure with anything more permanent than simple sun shade.
I guess you could attach your MP awning to the Airgo Lite giving loads of cover and flexibility if you add the sides too..