Hi-Q won't fit. I called them and asked about fitting KJ. you need a 10" grate for KJ.
They suggested the smoky joe replacement grate. I started with one and it works fine but would warp after a while. I just turned it over and let it warp itself back. I got another grate and use them both at the same time but rotate one 90 degrees and after 6-7 cooks it hasn't warped.