Most BSMD/DO programs don’t give merit aid.
Regarding outside scholarships, many colleges won’t stack merit aid. So for example if you qualify for need based aid (please do run those NPCs), and you do get an external scholarship, the college will reduce their need based aid package by the amount of the external scholarship. Some schools will start by removing the student contributions like summer earnings, loan and/or work-study which is a benefit of course. But you do need to look up this policy for every school on your list. Here’s Browns policy: Other Grants and Scholarships | Undergraduate | Financial Aid Undergradute | Brown University
You also might look into colleges with early assurance med school options and/or the LECOM DO early assurance schools