Added a servo to a friends prusa i2
https://www.youtube.com/watch?v=Yj_xLo_gsYA&feature=youtu.be
There seems to be some variability on full extension, I could see adding a rubberized stop at full extension so that the sensor is always at the right location when measuring…
the servo wires are with the motor wires and it is causing the servo to “pulse” i plan to try some ferrite filters first before i reroute the cables
Looks like you missed the line in the config to disable the servo after each move, that will stop the jitter you are getting 
Gotcha, that makes sence