If teachers are to mark the summer topic exams that school may or may not choose to set, and they are marked by teachers, then will the kids be told their marks for those tests immediately or will they have to wait for grades day. How will teachers decide the weighting of those tests compared to other assessments they have for each child in deciding a CAG.
Also won't grades this year that are being judged 'as is' in June look really bad next to last years grades. These kids are only one year apart, they will definitely have to compete using their grades in years to come.