It results in an attachment similar to ObjectXY but with the XY plane translated to pass through a selected vertex.
It is most useful to place sketches: pick a plane (XY, XZ, YZ) or another sketch then select a vertex to automatically translate the sketch in its Z/normal-direction. In contrast to the Translate attachment/map mode it does not move the origin in 2D/Sketcher.
Add ParallelPlane attachment/map mode
It results in an attachment similar to ObjectXY but with the XY plane translated to pass through a selected vertex.
It is most useful to place sketches: pick a plane (XY, XZ, YZ) or another sketch then select a vertex to automatically translate the sketch in its Z/normal-direction. In contrast to the Translate attachment/map mode it does not move the origin in 2D/Sketcher.
Here's a screenshot:
This is basically the same change that I proposed and was just merged into FreeCAD main: https://github.com/FreeCAD/FreeCAD/pull/14372