What I felt was missing in the initial argument around the detrimental nature of speeding through levels is also how different everyone’s initial level of Japanese is.
This is again something that’s been brought up before, but essentially, if you are completely new to Japanese you have a much bigger hurdle to get over, just in the initial levels of WaniKani, but also moving up the levels. There is just so much new information to process and internalize. speeding is not going to allow you time to process all of it! (most likely).
Meanwhile, there are plenty of users (me being one) who start using Wanikani relatively late into their studies of Japanese. Obviously, speeding through the initial levels is going to be easy (I estimated that around 90% of vocab items were old information for me, and plenty of kanji I new both readings and meaning for though not the kanji). That a very different learning situation from the beginner facing those levels. Speeding is here a breeze (most likely).
But, the difference in workload also continues up into the levels, especially with vocab items being things that I had encountered from my many years of immersion learning outside of Wanikani (anyone interested in the details can check out my my lv 60 post ^^). Again, a new user must devote time to do immersion learning parallel with WK to make the most of the lessons, not to mention learning grammar, doing listening practice, etc. That makes it less possible to speed through WK at the same time.
All in all, how you tackle WaniKani and manage to get to the end, is going to be an individual thing. For some users that means doing WK in just over a year is very much possible without loosing any sleep on it. Other, need to take a slower pace to make the most of the app, but also to suit their in real life needs and circumstances.
You must make the judgement yourself of what your pacing should be in the end - just make sure it’s something you can keep up for a long period of time as WK really is a marathon.