Ethics committees often do push against these.
I'm autistic, and hyperverbal. My son is autistic and pre-communicative.
I know that from a parental perspective there's a sense of desperation to know, and want to prepare a child in the best way possible for success in life and to help them develop, as well as the utter exhaustion of being a parent carer for high needs children.
Ethically though my child couldn't consent to clinical trials and I would have to consent on their behalf. Consent on someone else's behalf when they already don't have a voice is further taking choice away from them.
It's an entirely selfish motivator to want to consent to something that is experimental when you're consenting for someone else to undergo that treatment.
My son has speech apraxia as part of his autism but he isn't unhappy and not all communication is verbal. He's at his most unhappy when his needs aren't being met, and it's easy for his needs to be met when people take the time to educate themselves about autism without having to undergo ethically unsound clinical treatment in it's infancy.
I object to the phrase aspie supremecy but it is a term widely used to acknowledge the privilege that lower support needs individuals have in advocacy compared to our high support needs individuals and therefore as someone who has lower support needs than someone who is non-verbal with lifelong developmental delays, I would want to protect them from treatments and testing in which they can not consent.
The stakes in clinical research in autistic people has historically been used as a stick to beat autistic people with. In institutions, historically, and let's not forget about Herr Asperger himself.
It has all been deeply routed in eugenics and mistreatment.
I'm not so desperate to know the cause of autism, but I am desperate for society to find ways to support our autistic people reach their own individual fullest potential and support the parent carers of those with the highest needs.