@SaphireNY The problem is that every school is somewhat different, and the information available is spotty at best. You really need to research the particular school to understand how it works, you can’t just go off the ED admit percentage to see what the advantage is because the pools are different, how various hooks and tags are handled is different, etc…
And the schools (at least most of them) aren’t interested in disclosing the exact details because they are using ED for their own purposes - not always just nefarious yield stat juking, sometimes for more valid reasons (managing financial aid burdens, athletic or other special requirements recruitment, determining applicant commitment, etc…)