Honestly, you will need to contact each of these schools directly for the answer.
I will only comment on the ones I know.
Boston Conservatory/Berklee - even if they allow stacking…don’t count on getting a lot of aid to attend.
Boston University- no stacking. A merit award will reduce your need…and therefore your need based award will be reduced. Some music students DO receive both music performance, and academic merit awards…but both are merit. They would reduce need. But do call BU and ask. My info is from when my kid went there.
Columbia University and Barnard- no stacking. And they don’t give merit awards. If you receive an outside merit award, you must report it to the school. Your need based aid will be adjusted.
University of Michigan- I don’t believe they allow stacking.
The number of colleges which allow stacking is actually pretty small.
Also, schools that do allow stacking will not allow you to use your awards to meet your family contribution as they determine it to be. They still expect YOU to contribute that amount.
Really, your best bet is to contact each of these schools and ask.
We toured 28 colleges with our kids and only two allowed stacking…University of South Carolina, and Duquesne.