FWIW, Keston's K rate in the minors this year (small sample size) has been 25%, which is a little lower than it was before he got called up in 2019. Meanwhile, his K% across July and August in the majors is 32.4%. Obviously, you'd like it to be even lower, but that is in a range where, even if his BABIP regresses, he should still be very productive with his elite quality of contact.
Also, watching some early 2022 Hiura video today, I've noticed one particular adjustment he's made in-season at the plate. We all heard about the reduced leg kick in spring training, however, in the last couple months or so he's also switched his batting stance from open to closed. That change coincides nicely with his summer hot run....
In all, I think the lost Hiura of 2021 is in the past. The real question here is whether going forward we will get more of the 2019 all-star version or the 2020 mediocre version. Overall, judging by his contact stats, which rival his 2019 season, I'm inclined to think we're moving towards the all-star version. Probably still short of that with his K rate, but someone who needs to be in the lineup quite regularly, particularly against RHP.