I find it interesting that DSs independent, academically selective school does not do early entry for GCESs
Quite. The only early entry most super-selective do is maths, in order to do FSMQ additional maths in Y11, but some of these schools don't do that and it's a matter for some debate as to what's the right way.
And yet schools flirting with the floor standard measures, and without the advantage of only dealing with the top 2% of the cohort, enter pupils a year early for a wide range of subjects.
It's all most puzzling. One would have thought that schools with brighter children, taught in smaller classes, with a much narrower ability range, and (for practical purposes) zero SEN, would be more likely to be able to take exams a year earlier than other schools. And yet they don't. I wonder why now?