Hi Larry
The really simple way is to
1 Select section Viewport and use convert copy to lines ( hidden line render) this is almost instant as it uses the save viewport cache ( if you have it selected in preferances )
2 Paste in Design layer and use scale object ( viewport is 1:1 ) , so if you need it @ 1:100 scale by X 100. Design layer should be set at 1:100 before you paste.
This is much much faster than the old cut 3d section, and allows you to use the updated Viewport repaste, if you make changes.