yaw

Does anyone know if the DJI screw replacement set comes with the grub screw for the yaw arm? and if not what the size may be? I cant seem to see it there but apparently its "all the screws needed" from what ive been able to attain from google.

I have the latest firmware update and while adjusting some gain & expo settings, I noticed an option to change the Yaw Endpoint setting. This is set by default on 150 but can be adjusted between 100%-150%. Can anyone explain what this does and how it effects the P3A? Thanks!!