FWIW, consider that some of these students may need the accommodation specifically because of the pressure of the final exam. Many mental health disabilities will become worse with stress. A low stress environment and a high stress final exam could trigger entirely different symptoms.

For example, I have OCD (real, diagnosed, not the bs "omg im so ocddddd"). I have extra time accommodations because I have to spend time dealing with my OCD symptoms. With treatment, they tend to fade into the background. They re-emerge only in high stress situations. I would seem like a perfectly normal student in class, but then clearly start struggling with these symptoms if you watched me take an exam. Consider, many other students you teach may have these same experiences.