Are admissions officers of a school like Yale (who require all standardized tests taken to be submitted) aware when a student uses Score Choice to “hide” a score of a test they did not do well on?
If a college requires all scores, you should comply. As to whether the college can find out if you hid a score, it depends. College Board (SAT) does not provide anything to indicate you even took a test when you exercise score choice. However, there are many high schools that put all your scores on the official transcript sent to colleges. Thus, if yours does so, having College Board withhold a score will accomplish nothing except to prove you withheld a score when your transcript shows up.