This is a super interesting case of how outdated ideas (ie. knees can _never_ go over toes) become pervasive in people's minds, almost to the point of a myth that is very hard to dispel. The story of kneesovertoesguy is amazing btw, I recommend checking his podcast episodes/youtube channel and training program (https://www.atgonlinecoaching.com/) which focus on knee and lower body strengthening that uses exercises that were a no-go for many experts not too long ago.

(EDIT: sorry for the plug, I'm not related to kneesovertoesguy or his business in any way -- I just noticed the landing page I shared above is literally a call to pay for his courses. I'm not and never been a subscriber but do enjoy and have been seeing real benefits from doing exercises he goes through on his youtube for free. So I hope it helps!)