Hi Pierre,

re:
> If I start dragging in empty space it (of course) also selects the outer part.

But that won't be the case when you're doing a boolean difference because the outer part will have been already selected previously and won't be targeted for selection again at this point.

There's a mechanism in MoI called "selection lock" which is used to screen out objects that were previously selected to avoid this type of problem.

- Michael