Basically make a variant of the current Variable system where the Variables you set in one scenario remains true for any other scenario as long as these scenarios are linked within the same campaign through the Campaign Editor.
I don’t know if that’s something possible at the moment, but this simple feature would take Campaigns in a whole new dimension as choices you make in one scenario could basically bring consequences in later scenarios of the campaign, and increase dramatically the options of the player.
That used to happen in Janos yunadi campaign but now it has been taken down (it was very bugged). But I think the creator used genie editor or some other trick. For sure it would make custom campaigns more interesting if it was possible in regular scenario editor.