Should I ask for a MR?

I've just transferred my son from DLA to PIP and with the help of your guides have enhanced rate on both which he also had on DLA, so very pleased. For the most part the scoring is as it should be. However there are two sections Managing Therapies and Preparing a Meal where the information I have submitted provides evidence which has been ignored. For example, both on the form I filled in and also on his FACE Assessment it says in those exact words he cannot make or prepare snacks or a meal. Yet they have scored him he can make a snack or meal with assistance! Also on the Managing Therapies they have scored him as needed help and assistance for up to 3.5 hours a week which is far less than he actually has. He attends a specialist college where he has hours of therapy delivered directly and indirectly, we do more at home eve and weekends and then on top of that the treatment of his skin condition takes half an hour a day at least, administering meds for his epilepsy and monitoring that, none of which he can do. So my question is. Even though it won't get him any more money in benefits it is worth going for a MR try to get the scores to more accurately reflect his condition? It makes me so cross that they have scored him low when I've clearly given evidence to the contrary.