That's obviously needed and i don't think it's even time consuming to do that. The lack of this feature prevents me from being able to do general events without file editing because the number of countries is insane.
He should also add temporary ones for making scenario creators' job easier, i think.
Anyways, those definitely need to be added in the game. It would make scenarios much more interesting.
I don't know about the other plaftorms but, in the Android version, creating a new scenario with a different name results in a different scenario. He can try editing only one thing and see if it overwrites,.which likely isn't the case.