Indeed. Glad to have been of help.
I remember hearing it during my classes and crossing paths with it during my very incipient readings on the subject. I am not absolutely sure about how that specific name came to be, I only know that it has been tried to be proved that references to that specific name are contained in Columbus signature's acronym and especially in the strange and mysterious monogram he putted on the left side of the said signature.
To be honest, that seems like the weakest link and argument in the whole "portuguese" thesis, at least from my outside and ill-informed perspective. I think that the whole process to identify a name by very vague clues is more of a mental semi-fictional exercise than a historiographic one. A single letter can mean a lot of things, even when we try to create some link to the cultural background and to the other letters that are used in the same acronym, so I am quite skeptic of making those kind of jumps and interpretation. But the origin of that name didn't came from that maybe-not-so-credible clue, it came from somewhere else. I will make sure to ask around with my Exploration colleagues and professors. Once I get an answer, I will get back to you
To be honest, here between us, historiography is incredibly subject to partiality, even when things aren't done in bad faith. Given its off-topic nature, I will put use the "hide details" feature on my take on the issue of historiographical subjectivity.
Before anything else, historians work with subjective perspectives (when it comes to written sources) or very incomplete shreds (when it comes down to material/archaeological evidence) of a past that we can't really reach. When Suetonius or Cassius Dio write about the history of Rome, they are writing from their perspective, choosing what is worth mentioning and what isn't, identifying a causal link between events that is obviously a subjective construction, putting their own ideas, philosophies and partiality in the work, etc. We aren't reading what happened. We are reading their perspective and their narrative construction concerning what happened. If nowadays we can't reach a consensus about what is happening in our countries and world, how can we expect a different reality concerning past sources? And then, there are many things that we never know about (the whole system that the Romans used to clean their bottoms is only known, as far as I have been lead to believe, because of a single accidental reference that reached us, had that specific document been lost, and we would never know a thing as simple as that... why? Because for the Romans would be strange to explain how they did daily hygiene, because it was a universal thing).
And even if we can put aside the subjective and incomplete nature of our sources and findings of the past, we are still stuck with the fact that historians are humans. And even the best historians sometimes drop the ball on their narratives, having "weak links" in the narrative and logic chains they use to give order to the past. And even if we get the possibility of error aside, we are still stuck with the fact that historians don't live in ivory towers, growing up and living isolated from their society, from their age. So we end up with historians that are a clear product of their time (its ideas, its conflicts, its problems, its beliefs, its ways of thinking, its linguistic and mental structure and limitation, its way of thinking) and that do have a good dose not only of their geographical, political, economical, cultural (etc.) reality but also a subjectivity that gives them their own ideas, problems, ideals, interests, readings, beliefs concerning their own world. All that is bound to end up, even if only a little, in historiography, not only concerning what is said and how the past is interpreted (two equally intelligent people will not necessarily reach the same conclusion or interpretation of the same text/clues), but also what is researched and from which perspectives.
So yeah, even if historiography is constantly walking towards a bigger scientific methodology and objectivity, full objectivity will always be impossible, because historians are subjective and individual identities dealing with subjective and incomplete records of a past that is impossible to reach in its fullness. And that does show in past (and certainly current) historiography. In what they analyzed, how they analyzed and how they interpreted the same things that we are now reinterpreting. So my recommendation relating that issue is the same I received in my first day of college: "trust historians, but don't trust anything they write. Doubt everything"