I agree with you regarding Kiper's board and mocks. But, playing devil's advocate, I think those changes occur based on what teams share with him about the players.
They do but then they aren't 'his' really boards.
We've always had people who stated the board was consensus based and others who stood on their film.
Kiper is supposedly a film guy.
I know he hates the ESPN requirements to release them so early and that has softened my stance a lot toward him but I'm not a fan of major yoyo-ing on prospects.
You either like a guy or you don;t and a few slots as others rise makes sense but insane guy being top 10 then off the top 25 for absolutely nothing is just weird.
Goose Gosselin used to do a great job of this where he openly admitted his boards were based on scouts takes. He never got up which scouts so he kept access to that data to build his boards.