This was our son too! Sharp dresser, nice, clearly intelligent. He could fake his way through in the elementary years, but middle school/hs were rough until diagnosis and then he still had issues that didn’t magically become better but we understood that he wasn’t doing things to “push our buttons” and that he really did have a very different way of thinking in some areas. Based on tv portrayals–“The Good Doctor”, “Atypical” and my new favorite netflix “Extraordinary Attorney Woo”, it seems like those with ASD all have physical quirks that make if obvious that they are on the spectrum. That is not the case with my son.
If you don’t already know about the Sunflower Program check it out. It helps identify people with hidden disabilities to airport staff and other locations. We received a free lanyard from the MSP airport in case my son needs to travel. That airport and many in the country have been trained to identify these people in this subtle way and understand that they may need more attention. The state of MN also has a place on the drivers license to self identify ASD. It is an option. My son chose to put it on his license and it can be removed. After we discussed the option, he decided it would be good to have on there in case he were pulled over by a police officer and his behavior was not typical.
OP-Good luck. I hope your friend is able to find some answers.