I can also attest (as someone who’d mostly focused on WK) that level 60 doesn’t = being able to read if you don’t also do grammar. And while the vocab in WK is an excellent base, you really do need an additional source like the Core 6K which has kana-only words. And it’s not just learning new words, it’s learning the multiple possible definitions (just look up 掛ける!) and the contexts in which they’re used.
But this is all made so much easier if you’ve had exposure to the kanji before. WK doesn’t have every one you’ll come across, but it does have the great majority. I say exposure because burning does not mean it’s ingrained to longterm memory unfortunately, but it won’t be foreign at least. I don’t regret going full speed but it’s definitely not necessary - consistency is key though and helps with the SRS. So make sure to keep up with the reviews, and find the interval for new lessons that you’re reasonably comfortable with.
Looking back, I was too lenient with the amount of time it took to recall the answer. If I was doing it again, I’d type something wrong if I couldn’t remember right away and move on even if it cost me my levelling up in time. So I guess that much I do regret.
Hope this helps!