https://swarthmorephoenix.com/2025/12/04/jim-bock-90-sheds-light-on-admissions-process-early-decision-challenges/
In this artile, Swarthmore says 25% of their class are recruits. So that's already half of the ED class. It's ED acceptance rate is about double its RD acceptance rate.
So recruits alone already render any ED advantage for unhooked to close to zero. Then there are other institutional priorities.