Comment 9 for bug 1251393

"The same rules and issues apply for just defining the board outline in pcbnew directly"

Not really true.

As I said previously, a board outline has constraints.

When you create the board outline, you know the grid size, and you are able to create a closed polygon.

This is not the case when creating a footprint.

Some time ago, creating edge cuts in footprints was allowed.
The main result was bug reports about not closed board outlines.

What is the interest to allow things in pcbnew, when these things are broken?