Hi Pilou, looks like you are having fun with booleans!

One interesting thing is that history will work for the case of boolean intersection between auto-extruded curves, so if you turn on control points and edit the curves for your intersection case, you should see the object update.

This is because this particular case does not delete any input objects, it only creates new objects. Deletion of the input objects is what normally breaks history right now.

- Michael