I'm trying to figure out differences in meaning in nuance among all the ways to express X that Y.
"It's a problem that you're late this often," or "That you're late this often is a problem."
"The most interesting thing was that the main character was the criminal," or "That the main character was the criminal was the most interesting thing."
- Do these guidelines for choosing の/こと apply to the use of ということ and というの? If so, those guidelines don't seem to be followed in a lot of the example sentences I've read.
- Am I overcomplicating this? I've read and heard suggestions it's as simple as: の and こと both correspond to "that" when used as complementizers, and the preceding という just serves to highlight or foreground the clause appearing before it. This answer seems to jive with that interpretation.
- Building off the previous question, and at the risk of sounding like I'm requesting the shameful "word-for-word translation" -- could it be as simple as, こと and の (with their respective restrictions as nominalizers) correspond to "that," and という+nominalizer corresponds roughly to "the fact that"? As in: こんなによく遅刻をすることは... would mean that you are late this often..." and こんなによく遅刻をするということは... would mean the fact that you are late this often..." Is this correct?
- Ultimately, what I'm trying to figure out is the differences in usage/meaning/nuance in the following sentences:
I know there must be a few dozen explanations on the internet, including a lot on stackexchange, but they often don't agree or they only cover phrases like "so that means..." rather than complementizers.
The most thorough explanation I've found is in the Dictionary of Intermediate Japanese Grammar.
The way they it treat it is sort of convoluted, though.
S to iu koto wa is used when the speaker / writer views the content of S at a conceptual leve!・ Specifically, S to iu koto wa is used (1)when S is unlikely or impossible (e.g・,KS(A) and Ex.(a)), or (2) when the speaker / writer concludes or attempts to conclude s.t. from S (e.g., KS(B) and (C), and Exs.(b)-(g))・ First, S koto cannot be used when S is unlikely to happen. In this case, S to iu koto is used, as in . a.彼がこの集まりに来ない｛という/*0 ｝ことは考えられない。 (=KS(A)) b.これだけ丁寧に説明すれば,分からない｛という/*0! ことはあ り得ない。(=Ex.(a)) Third, if S represents something likely to happen, both S koto and S to iu koto are acceptable, as in , In this case the speaker / writer may view the situation at either a concrete level or a conceptual level.  彼がこの集まりに来ない｛0/という｝ことは雜かだ。 (It is certain that he will not come to this meeting.)
I didn't see an explanation of exactly what the authors mean by "conceptual" and "concrete," and there doesn't seem to be a corresponding section for というの used to mean "that" or "the fact that."
Other explanations seem to disagree with the DIJG.
Interestingly, I've seen a number of questions on hinative about の/こと/というの/ということ used as complementizers, and a lot of the native answers are literally just "こと is natural." I feel like that has to be worth considering if it's straight from native speakers, but I wonder if it might fall short when you're trying to enable yourself to use Japanese for professional purposes in professional settings.
And then this answer from a native here on stackexchange suggests it's the other way around.
My current theory is that out of the examples above, こんなによく遅刻をするというのは問題です sounds most natural/is most grammatical because the addressee being late and that being a problem occur in concert (の) and because という foregrounds the phrase it nominalizes, which seems in keeping with the speaker's intent.
Thanks in advance for any help you can offer.