If a teacher is questioning whether a student needs access arrangements, it is surely their duty to raise that with you? I would be concerned if the emergence of problems in Year 10 was seen as ‘too late’ for access arrangements to be considered. Pressures inevitably increase as GCSE standard work is demanded.
There is plenty of time to establish ‘normal way of working’ before the final exams.
Of course all access arrangements need to be appropriately validated. They should never be awarded to provide ‘unfair advantage.’ Their use is to try and restore a level playing field.