Are AOs aware of all the possibly cheating incidents (AMC, SAT, ISEF) and able to tell?

IMO: Are they aware, sure.

Do they care? Questionable to likely not.

They are not police officers. It’s not their job to investigate if an applicant may have cheated somewhere, or sometime in their life. Now if an applicant was caught and there is some notation, then that is different.

Like most things in life, people who read and evaluate applications are told to make a determination on the merit of what is available.