Hi Chloe
You can tell them what you think you should score, but at the end of the day, they will award whatever score they think is appropriate, regardless. They will make their decision based on 'evidence', not your view. That means your current score could stay the same, could be improved, or worst case scenario could be worse (though that rarely happens). What I'm trying to say is that they are not affected by how you score yourself.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems