I am in my second year of a masters in clinical psychology. I registered for accommodations last year (MA1) for ADHD and comorbid anxiety, but found that the accommodations didn’t really apply to my program (unlike in undergrad). As to whether or not it will be useful to you will depend on a) the types of accommodations you need, and b) your program structure. For myself, in my undergrad I primarily used my accommodations for exams/tests, and my graduate program was primarily participation/assignment based, so my accommodations were not nearly as applicable. I also found that my graduate program had more flexibility with deadlines, so I was able to get extensions as needed, with enough notice.
The good news is, in many post-secondary institutions (at least in Canada) it is up to the student to reveal that they need accommodations to a given instructor, so if you end up not using the accommodations, no professors will know you are even registered for them. Given this, and the fact that you won’t know the structure of your program until you are in it, I recommend setting up an appointment with your institution’s accommodation’s office to discuss disclosure policies, and assuming the policy is non-disclosure without consent/you are comfortable with the disclosure policy, go ahead and register, even if you aren’t sure if you will need the accommodations. And as an aside, a few specific accommodations you may want to consider asking for given your ADHD/audio-processing combo are permission to audiotape lectures for the sole purpose of note-taking, and access to instructor powerpoint slides (the latter is something most profs allow anyways, but this is a backup just in case).
The other incentive to register is that even if you don’t use your accommodations, your institution’s student accessibilities office may also provide access to additional resources only available to registered students. For example, our school’s accessibility’s office offered free workshops on stress management/study tips/etc., yoga and meditation classes, therapy dog visits, private writing rooms, etc. only available for registered accommodations students, and while I admittedly didn’t end up using any of these in my first year, it was nice to know they were available to me.
Finally, it is good to keep in mind that if you are registered for accommodations and end up disclosing that you need accommodations to a professor, it is very unlikely that you have to disclose as to why (though be sure to check your school’s policy), so this may be reassuring if you are concerned about stigma specific to ADHD/your other diagnoses. And if it’s helpful for you to know, I suspect I will again register for accommodations, despite not having used it last year.
Hope it helps, congratulations on getting into your program and best of luck in the upcoming year!