For a bit of a contrasting view, I’m moving pretty fast (8 days per level, which is not as fast as possible but is pretty close) BUT I had significant Japanese ability before I started. Looking at my next level (20), out of 33 Kanji, only 7 are completely new to me. At least half I already have down, and the remainder are ones that I’m iffy on, maybe I only know one reading or I’m only clear on its meaning in english or I only know it in the context of a single word but not super clear on what it means by itself. For vocab, 70-80% are words I already know.
WK is pretty easy for me to plow through right now because so much of it is just review; if I was starting from zero I would definitely be pacing myself more. As I move into the 30s and 40s I know that my knowledge is a lot weaker and I’m going to run into a lot more words and kanji that I don’t already know, and I might decide that my current pace is too fast and that I need to slow down to keep things manageable. The most important thing is to be consistent; if you go too fast it’s easy to burn yourself out.

