That's OK, paraphrasing Jane Austen, it is a truth universally acknowledged that Kazuki's spins aren't great
The scoring really varies, though. At Nats 2019 he lost a lot of points on spins, even in the FS which was a great skate. Some spins were given level 4 at first, and then downgraded a lot on review. Whereas at Nats 2020, I agree, maybe they were a bit too generous with his spins at times (while being absolutely stingy in PCS and jump GOE

)
My personal theory is that spins are tricky to judge anyway - sometimes an ugly-looking spin can have all the features of a level 4, while a pleasant-looking spin can have level 3 or lower features. In Kazuki's case, his spin positions are so messy that it makes the judges more prone to errors - it's more difficult to distinguish the features, such as the number of rotations in a certain position

I think that's why you have this variation in judging depending on the competition, sometimes the judges give him the benefit of the doubt, sometimes they don't.
In any case, he never gets great GOE on spins anyway, and whatever 'extra' he might get is nowhere near enough to offset the scores he should be receiving in PCS and sometimes jumps. So, despite this spin issue, he's still a very underscored skater overall