You glossed over my point. I’m not using it as a “crutch” for reading. I’m using it to have notation for the stem — the thing before -u. I could choose alternative notation with kana (e.g. just always using the -u ending, or the idea of variable stems like i-stem and a-stem) but then the visual “gluing” wouldn’t work. Which is the whole point of mental model I’m communicating. It’s fine if you don’t find this mental model helpful but it’s the point of the article.
I’ll be honest that I also wanted (as a challenge) to write this article so that a person with zero Japanese knowledge would be able to correctly conjugate almost every word to every ending. This is more of a teaching drill for myself though but it’s another reason for the romaji choice.
The explanation made sense to me: romaji works well for vowel shifts (as the vowels aren't glued to consonants) while kana works well for consonant shifts (because the vowels are glued to consonants).
Latin text's smaller tokens/phonemes have advantages and disadvantages, but they are a convenient notation for getting the author's point across.
The difference in phonemes reminds me of how game designer Naramura came up with the (Spanish-sounding) name "La Mulana" for his game by spelling his name backwards in kana. In romaji it would have been "Arumaran" which is completely different (while in kanji it would have been "Muranara".)
> while in kanji it would have been "Muranara"
Not quite. If you change the order of some kanji, the general case is that the resulting text has no definite pronunciation. You definitely would not expect that the sounds assigned to the kanji in one ordering would be the same ones assigned in a new ordering.
This is a phenomenon the Japanese sometimes play with. In the novel Musashi, Musashi comes up with that name by reinterpreting the characters of his actual name (which, in the novel, is Takezō).