I think you can appeal on the grounds of “unreasonable academic judgement.”
What concerns me, is that some schools (particularly selective schools where the grade profiles don’t vary much year to year), have simply “fitted” students into the normal yearly grade percentages achieved in that school to avoid investigation.
So for instance, if there’s 12 doing Physics and, in an average year at A-level, 30% generally get an A, 30% an A and the rest a B, they have just applied these percentages to the 12 - so that 4 get an A - because if they give A* to say, 6, they may be accused of grave inflation and attract an investigation.
They say there are no grade boundaries this year which makes it hard to appeal “academic judgement.”
But if a student has basically achieved 98% in the assessments they did between April and June, but still been awarded an A (rather than A*), is is worth appealing in the grounds of “unreasonable academic judgement?”