The Collapse Curvature U command allows you to create kinks with XirusCAD in the u direction. The curvature values at the selected point(s) will be set to 0 in the u direction.
You can call the Collapse Curvature U command from the XirusCAD menu, from the XirusCAD Toolbar or from the command line. Select the points on your XirusCAD surface. The curvature of these points will be collapsed in the u direction. This means that the curvature values at those points will be set to 0 in the u direction.
In the video, the Collapse Curvature U command is found under a different XirusCAD menu item.