I redesigned this throat plate eliminating the screw holes and lock (lock is not necessary to have).  I have fine tuned the bottom feet to be the exact height to level the plate with the table saw top (you can slightly sand these feet if a little bit height).  I have also added a riving knife slot.  The long blade slot is designed to be slightly thinner than the blade.  This makes it a true zero clearance insert by installing the plate with the blade all the way down, turning the saw on and raising the blade all the way up to cut the slot.  Print this with 5 walls, so that you still have solid walls on either side of the blade once the extra bit has been trimmed away during install.