This example part has a vertical surface, shown in red, with two tabs at the top:
This is the surface in more detail:
Using an Isoline strategy, with Tool axis smoothing enabled and a Tilt axis of Lean then lead with no Smoothing distance value, the tool has sudden changes in direction. For example, it machines the area below the first tab in a tilt position:
Then returns to a vertical position between the tabs:
Then returns to the tilt position to machine the area below the second tab:
With a Smoothing distance value entered that is long enough to cover the area between the two tabs, the tool stays tilted when machining between the tabs:
