Hi OSTexo, maybe we're talking about different thing for what "outline" means? In MoI's PDF and AI export there is an option to generate outlines, which is an additional curve that's generated where visible lines are adjacent to the background.

So with this:



The "visible lines" are like this:



And the "outline" is like this:



So as you can see there are areas where there's both a visible line and and outline over the same area.

Right now there isn't any concept of separating out "internal visible line" that tries to exclude areas that are on the outline. Doing that would be a new feature in the hidden line engine itself, not just something involving layer assignments to the existing drawing. Then I worry about the UI to control that, it can get hard to describe these things in a clear way.

- Michael