Your result
Possible
Mixed income puts you in the awkward part of this rule, and it is worth understanding why rather than just being told no.
The route is defined by reference to a foreign employer, and it expressly excludes someone who works for an employer in Brazil. So Brazilian-source work is not simply neutral alongside your foreign income — it is the thing the definition rules out. Whether a small amount of Brazilian work sinks the application is not settled in the text, which is precisely the problem: it leaves the decision to the officer rather than to the rule.
Which means there are two clean positions and one risky one. If the Brazilian work can end before you apply, so that your income comes wholly from abroad, you are straightforwardly within the route provided you can show US$1,500 a month from the foreign source or US$18,000 in savings. If the Brazilian work is central to your living, the work route — where a Brazilian employer petitions for you — is the honest answer instead. Applying as a digital nomad while keeping Brazilian clients is the version we would advise against, because it puts the permit itself at risk later.
On citizenship: residence is what the naturalisation clock runs on. Four years of it in the ordinary case, or one year if you marry or partner a Brazilian, have a Brazilian child, or hold the nationality of a Portuguese-speaking country.
Tell us the split between the two, and whether the Brazilian side could be wound down, and we will tell you which of those three you are actually in.