Gear cutting synchronization (for example, for finishing cuts, etc) is available as part of the myCNC software package.
https://youtube.com/watch?v=D9X-R_8v2iw%3Fwmode%3Dtransparent
As can be seen in the video, the myCNC controller only begins to move the rotation axis (axis with the gear) when the spindle is in a particular position – this allows for a precise synchronization of the positions between different cuts, allowing for finishing cuts on gears.