I tried the rocking fix when I had the seat out, Tightended everything in sight and didn't fix it, didn't even diminish the rocking..
Angleing the front of the seat Upward so you are tilted back eliminates the rock. Its not altogether uncomfortable and since I have yet to fix the rear height adjustment failure I can't raise the rear anyway so I just bring the front all the way up and the seat is not rocking.