more of a PSA than a review. i used these on a Kessler 185 with catek os1's and the Kessler suffered delam of the inserts, nonetheless. some have posited that these spacers will help protect a board from the sort of point load damage that is the nemesis of metal boards and my experience proves that to be a suspect claim.
i am no engineer but the utilization of longer hardware to extend the additional length necessitated by the spacers might have been a more detrimental than constructive, i don't know.
also, the spacers may protect the board's topsheet from indentation, but will actually promote hardwater stains on a metallic surface - for those interested in the spacer's application as an aesthetic protection, this is worth noting.