D is attending Davidson this Fall. Submitted 3 Subject Test scores. No way to know if it made a difference but the scores were high so we figured it wouldn’t hurt. Didn’t get merit aid (did at a number of other good schools) but did get more generous than expected need award (we are close to full pay).
General rule of thumb I recall finding while doing research on this topic: for top colleges def. submit scores 700+ and consider submitting 650+. But like many aspects of college admissions, who really knows, right?
Hope this helps.