> *RTK or “remembering the kanji” is a system that teaches all kanji before student learn their first word. It’s quite popular online as it lends itself very well to solo studying.
For those unaware, the OP probably means this three part series: https://en.wikipedia.org/wiki/Remembering_the_KanjiOne thing I have found over the years, I have never met a foreigner living in Japan who has used it extensively. (Many were aware of it, but few used it heavily.) However, there is a lively community of online learners who use it. (Don't read that as a judgement against using it; this is simply an observation.)
I was surprised to read this part:
> a system that teaches all kanji before student learn their first word
I have never heard this description before. I always thought it was a learning aid to use mnemonics to remember the meaning of individual kanji. If someone can complete all volumes of RTK before "learn[ing] their first word", I would be stunned. It would be a feat of super-human level of memorization and recall. That said, the Internet is a huge place with billions of people. There will be somebody, somewhere who took this path and is happy to tell you about their success using it.