Luke's suggestion is a very good one. I might use that if needed.
Yep murphaph, I was aware of that. But as bramble mentioned, there are some exceptions for Brazil with which one can get away with keeping the Brazilian citenzship. Eg, from what I read/heard, Brazil doesn't allow the loss of citizenship in case one's applying for a second citizenship in order to excercise basic civil rights which only the citizenship can grant. I coule state voting as one of them.
(Source: https://www.dw.com/pt-br/%C3%A9-poss%C3%ADvel-perder-a-cidadania-brasileira/a-42603277 - in pt-BR. I'll leave it here as a reference in case someone bumps into the post in the future)
But again, that's still a bit fuzzy to me and I just have to find out exactly what write in the application forms as reason why I can't renounce my current citizenship (still looking into it).
Btw, thanks bramble for that link and info! I haven't seen it before. I'll take a look.