What are my chances as a Double Legacy?

Says who? Is it like how schools are “need blind” but look at your address and parents’ education/jobs to get a sense as to how much money you have? Unless you have direct access to an AO willing to speak off the record (e.g. family member/close friend - which I do, albeit not at Brown) you cannot take anything said, and especially anything written, at face value. These schools get 30k applications, they do not want to read anything more than they need to. If they ask about something, that means it’s a factor. The Harvard lawsuit, even without knowing the details, should illustrate that. There is a whole lot to their process that was never disclosed at the countless number of info sessions and Q&As, etc.

When I applied, it asked for each relative. It was well known at the time that each increasing relative increased chances, that parent was the most, etc. I haven’t heard anything to the contrary prior to your post so the only thing that has “no evidence to the contrary” in my mind is that more family members and whom matters.

Brown alumni office has a free college consulting service for children of Brown grads. You might want to check that out and consider reaching out to them. It’s a very nice benefit that I only recently became aware of.