Z knob has longer screw inside (12mm). Longer screw can give a benefit only when Z motor damper is used because it lifts the motor and the rod up by 1cm.
Damper bracket/mount for Z motor:
For Ender3 you need to miror this damper and cut a little
Here I also attached my own mount but it is untested.
Exturder knob. In all designs I have found on TW I do not like that it can be mounted on very short end of the motor axis. So in my design I used one spare brass filament pushing gear.
After printing the knob just push gear into it. Then you can mount the knob on the motor axis and fasten it with the small screw that is in brass gear.