It isn't a good one.
When I looked at preclinical for one of their competitors, that was the exact same thing, the issue was study design. Specifically, you are shoving something up an autistic kid's butt once a day or twice a day. They only did this to the placebo arm for 3 days, and only to healthy kids, whereas the treatment arm did this for 8 weeks.
If I punched you in the chest as hard as I could once or twice a day, do you think you'd have a behavioral change? That's their endpoint. If I called it a "medical" punch, does that change anything?
Can an autistic kid learn how to answer a test to get the thing to stop being shoved up their butt? I think so. By all means though, I encourage people to make this risky investment if they think this treatment pathway is real. It sort of is! If you want a behavioral change, we have a good idea of a way to get that from defenseless kids. But not for a good reason.