To keep the knob from falling out and from ripping out the threads in seat(there is a update for that)drill a small hole in knob and ziptie it to subframe crossbar also dont tighten it tight just make contact with subframe.How often do you take seat off any how?
I think I fixed it. What I did is tapped the post with a 5/16"-18. Then I ordered some Rosette Plastic Head Thumb Screws from McMaster-Carr. Just screw them in and I was done. I guess I will see how they hold up. The screws costed $11.50 for a pack of 10.