He would still need to pay taxes in Brazil, and explain why it's not international money laundering. Same if the money touches the US, will have to pay taxes there too, then transfer it to Brazil for more taxes and paperwork.
I haven't heard of Stripe Atlas. And it actually sounds like a good idea.
I'll take a deeper look, but you could have a company in Brazil that interfaces with the company you create with Atlas. In none of my comments in this thread I am trying to aviod taxes BTW. Would be great, sure, but not the objective. I am impressed by the lifestyle the original poster, it inspires me, to the point I would like to be able to do it. Taxes need to be part of the equation, but being viable and practical would be the main issue.