Hi NaN,

re:
> Hm, on second thought I don't completely understand the explanation from the faq when looking at
> this concrete demo shape. For this example I cannot select any points at all.

Can you please post the .3dm file of your demo shape? Then i can point out the areas to you that are preventing it from having surface control points turned on.

But yes for a case like that it would probably be better to cut the circular hole inside MoI by drawing a circle and using Boolean difference, rather than doing the boolean in polygons in Blender.

- Michael