I don't kid myself into thinking that employers can't tell roughly how old applicants are. If they're asking for SAT they could also ask for college transcripts/graduation info. That's going to reveal the approximate age of many candidates right there. Finding out what year you took the SAT will add 0 info in most cases.

While I generally agree with you that employers should absolutely not be asking for this sort of information, they're still going to be able to make a very good guess at your general age by the dates of your education and employment.

Unfortunately, there isn't really a viable way to prevent employers from finding out your age from your resume/CV.