Incoming new 10th grader at Andover here!
From my experience, requiring significant fin-aid did not award me any disadvantages when it came to applying to Exeter and Andover. As a matter of fact, I gain acceptances to both schools with full grants.
You will not be at a disadvantage for requiring aid when applying to those schools. Andover’s need-blind and Exeter’s practically the same. The true disadvantage when requiring fin-aid here is filling out all of those forms…