This is a weird thing because you'd be hard pressed to find two languages as similar as Spanish and Portuguese, and whatever this paper has to say on the topic it'd be inevitable that the English translation in the middle would be "lossy".
I sometimes get disappointed when people suggest that machine translation is a substitute for actually learning the languages. It's true that we have limited time in our lives to study languages, and the machine translations can be a quicker way to get the gist, or possibly open some doors. But go much beyond that, like claims I sometimes see that you can wear AR goggles and suddenly communicate like a native, and you set unreasonable expectations. Or perhaps imagine a world where the way to read Shakespeare is to put it through a machine and it tells you, "statistically, Shakespeare meant to say this". Is that really reading it?