Exactly as Sarah says above , plus I used to give a staff presentation each year at start of year , about access arrangements, normal way of working , students who had support , assessments and what we had to do to apply for it. And what their role in the process was. So it was addressed in Y7 as a heads up!
Then I gave staff in Y9, and Y10 evidence sheets that they needed to complete to show what support students were receiving and used as part of the application process.
I feel your pain !