Objective scaling is not taking off screen feats and random statements at face value. That's just bias scaling.
I feel like something a lot of people get mixed up on especially when criticizing meth scaling as they say we should take into accept narrative statements like L's stock market feat no matter what but I find the arguments around that dumb and here's why. The reason why we don't take those type of feats seriously isn't solely because there's no explanation around it, it's because there is no proper way to actually EVALUATE the feat.
Debates and arguments revolve heavily around proper context, evidence, and facts. The more ambiguous and vague something is, the weaker the actual argument is. Any claim that it's objective scaling when you accept everything no matter how evidentiary lacking something is just shows you don't understand what objectivity is.
Please read the actual accepted definition of the word: expressing or dealing with facts or conditions as perceived without distortion by personal feelings, prejudices, or interpretations
By definition, you cannot objectively evaluate L's stock market feat or his feat of preventing WW3 because you DO NOT know anything about the facts or conditions that played in it and anything around it would really be your own personal feelings, prejudices, or interpretations.
You don't know whether he had to really push himself to a new cognitive level, you don't know whether the statement itself was exaggerated in some shape or form, you don't know whether or not it was only accomplished because of sheer luck, you don't know whether or not it was accomplished because he had a lot of help, was this WW3 even a serious problem that would've warranted nuclear destruction, was he dealing with one guy or an entire group, how powerful was this one guy or entire group, were they even going to directly cause WW3 or just exploit the current geopolitical environment which was extremely tense at that time for whatever reason, etc.
You can say ANYTHING about these statements and feats, which is literally subjective reasoning. You look at L stopping WW3 and you make the interpretation that "Oh, he must be super intelligent then" but then how does that make him super intelligent? Explain it to me.
Oh wait, you can't because you have no evidence to back up your claims. You have no evidence to imply that he had to make deep calculations, solve puzzles nobody else could, manipulate various people to create a certain event, deduce the overall truth while having nothing but a small hint....why must we assume this is enough to make deem him "smarter" than another character? For all we know, the culprit could've just gotten bored and gave up and let L take a free win.
The the argument I hear a lot which is "Well, I mean based on what is necessary to achieve the feat we can determine it required high cognition therefore we can co...." is faulty. Once again, you don't have no evidence to support anything you said. Based on what is necessary? You have no idea what the feat. required and therefore no idea what was necessary and what wasn't for him to achieve said result and anything else is just your own interpretation, not an actual objective statement that could be supported.
At least when we scaling something that was actually EXPLAINED, we can see for ourselves how sophisticated and impressive it was to achieve something because we can break it down with proper logic and reasoning. We can attempt to shatter and debunk the accomplishment as much as possible and then see how resilient it truly is depending on how much actually ends up breaking and how much ends up surviving. We can apply actual scientific thinking to it.
We don't have to rely on making a bunch of weird interpretations or random assumptions because most if not all the facts and conditions have already been provided to us. We can say with a lot of confidence that this character has truly displayed a high level of intelligence because we aren't relying on our "feelings" we are relying on empirical evidence. This type of reasoning is way closer to being objective than any other.
To me, it's not really about whether it's on screen or off screen or whatever. Who cares about any of that. What matters is whether we are aware of the context or have some evidence to back it up in any claim in some shape or form.
"An author contradicting himself bears no relevance on the narrative" bro..what?
If an author has repeatedly contradicted himself, then the narrative doesn't make sense and if nothing makes sense then it cannot be properly evaluated and judged because you can't rate or measure something that is inherently illogical especially not in an objective manner. Facts cannot be both true or false at the same time. If the author can't be bothered to take his work seriously, then I can't be bothered to take it seriously either.
Sure, one can say "Well, you just don't understand it and therefore have to cope", that's true. Except they themselves do not understand anything and are intentionally choosing to not even bother. If your scaling consists of using vague statements, nonsensical claims, and contradictory evidence then you aren't trying to argue in good faith at all.