Stereotypes are stereotypes for a reason. I have Aspergers which is a form of Autism, and I very much fit all stereotypes save for one. The key, much like real life, is focusing on the strengths so you can compensate for the weaknesses.

I don’t have experience with Down syndrome myself, but think about if you were in there shoes. If you knew that you learned things slower and communicated slower than your peers would you rely on those for day to day life? No, you would compensate in some other way. When people say blind people have super human hearing, they don’t. They’re just compensating for not having sight. When people say kids with Aspergers are super smart, I can personally attest that we are not. We just are compensating for our lack of people skills.

Any “disability” will be like this. You have a shortcoming that no one else has to deal with, so you compensate somewhere else. If you want people with “disabilities” to shine in your story, focus on their strengths and have characters around them who can prop them up in their weaknesses. That’s definitely a conversation you need to have with your table, because if there’s no one, or no way to compensate for a weakness it’s like trying to build a house with sticks and stones. You’re basically going to end up with a hole in the ground, functional, but royally sucks. The surrounding people are extremely important to a neurodivergent’s success as that is what gives them the tools to build with, and if you have tools you can build a proper house.