There are a bunch of universities in the US where for the strongest students admissions is essentially unpredictable, and for everyone else admissions just won’t happen.
A 3.92 unweighted GPA plus a 1500+ SAT puts a student into the “academics is good enough” camp pretty much anywhere (760 math might be slightly low for literally two schools in the entire world, Caltech and MIT, but even there might not quite be a show stopper). After that other factors become important, such as research experience and references. Your son excels on these “other factors”.
Welcome to research!
Welcome to having a child involved in research!
What is the difference between having a child who works in research versus a child who works in medicine? With a child who works in research when they talk you don’t understand what they are saying. With a child who works in medicine (whether human or veterinary), when they talk you wish that you did not understand what they are saying.