When you draw with a 3D sketch in 3D, you can divide for two or four. In particular, this makes work easier if you draw with spline and manipulation is a bit difficult.

Additionally, by right clicking on the splail point, you can enable the option Show a sketchbook triad, which makes it easier to move such a point.

Splitting the window results in this, that grabbing the splinter holder in a given window, We only move it in a visible plane, e.g. XY.

Facilitation is particularly easy to routing when drawing cable routes and advanced surface modeling based on U-V curves.