Mid motor also helps keep the front wheels down when accelerating and stops the car handling like a pendulum with all the weight out back. It also keeps all of the electronics inside the bodyshell which protects all of the wiring etc. Kinwald seems to be doing ok with his mid-motor Xfactory so I don't thing its anything to be concerned about.
I can't remember the last time a rear motored car won a national in the UK. This looks like a beast and I can't wait to get hold of one