By the way this may not be the best place to offer this feedback but just in case: I don’t understand why 誰 is all the way up to level 43. In my experience it’s an extremely common kanji that I’ve encountered all the time including in very beginner-oriented grammatical explanations. IMO it belongs earlier. I expect that most learners will already be familiar with this kanji long before they encounter it in WK.
Similarly 彼 I think is extremely common in sample sentences (either alone or as part of 彼女) and could be lowered a bit.
Basically in my experience these words are disproportionately represented in grammar books and for this reason alone it may make sense to teach them earlier. They’re also not particularly complicated kanjis from a radical standpoint.
There’s also 俺 which IMO belongs to a level lower than 44 because it’s everywhere in all sorts of Japanese media, but I understand that adding yet another “I/me” kanji in the lower levels, and one that’s a bit rough on top of that, may be more confusing.