Are early applicants prefered for merit aid?

Case is a striving school - and it should be. There will be merit aid for regular and EA decision applicants. Their recent entree into ED makes a lot of sense for the school. But, I suspect that it results in no merit money for applicants. If I’m wrong, I would be very interested in details from those who applied ED. Our son was a strong EA applicant several years ago (before ED option) and he received half tuition. I suspect if he applied ED he would have received none. Appreciate others’ thoughts.