Some time ago, up until iwas about 40ish level, I used to do all lessons, all about 60-100 of them per level in one day.
in hindsight, I am not sure it was good idea (for me at least), unless you very serious about Japanese to the point, that nothing else matter and even then you could use that time to learn grammar and dissecting sentenses, speaking and listening.
It was hard time and I suffered some consequences, by still confusing one or two kanji and words between each other.
I recovered more or less though with lots of pain.
But Apperently there are some beast like breadstick ninja and some others who did just fine and get 50 level(maximum at the time) with out my sort of problems,as far as I know, in about one year.
However, the same breadstick, from what i saw in his posting, still had to do a lot of reviewing each day. About 300 or so a day, I think.
So you have to, perhaps, choose whether you want to investing some time on a daily basis.
Reorder ultimate, third party wanikani app, can, I guess, mitigate many problems of this route.