That’s a bug with Grease Pencil, Guillaume.
I was hoping that no one discovered that, but I’m impressed that you did.
It tells me that you are really pulling things apart to figure out they work – this is a good thing.
As for the bug, I actually forgot about it and never reported it.
But it’s worth me digging in again when I have time to find the root cause – and/or experiment with actual cutouts that you can do these days.
I have started coding in c++ to fix bugs and add features to Blender, but not in the Grease Pencil module (that is beyond my knowledge)
