Why is my smooth shape extending beyond the Design Space?

The optimisation has a fully automated smoothing algorithm integrated which is very important to generate a good & printable surface. In order to have all of the defined elements included in the geometry, the smoothing takes place after the optimisation process and includes more material around the Non-Design Spaces per default (automaticFunctionalFacesDetection.positiveNonDesignDirection=true for more information have a look here) as well as all the created Machining Allowances. These geometries extend beyond the regular Design Space which is exactly what is needed to generate the intersected geometries for the nominal geometry and the print geometry. All functional surfaces have clear and sharp edges as well as clean functional surfaces.