In my case, I did clone the insert that came with my Grizzly G1023RLWX. There is no clip or anything on the original insert to hold it in place. There are four set screws for leveling, but that is it.
I plan on adding some type of clip or extension that will inhibit lifting of the rear of the ZCI insert I made. I wonder why something like this has not been incorporated in the Grizzly design? Perhaps because the opening for the blade and riving knife is so large that having either lift the insert is likely impossible?