The global directives are a nice to have but in my opinion they are not agent friendly. The two I like the most are Hard to earn and fog of war. Recently I have noticed that the hard to earn has been removed from the global directive. And I am not sure why they did this. Can you put the hard to earn global directive back?
They rotate some of them each season (I think there are two different ammo-limiting directives, two different skill-limiting directives, two different armor-limiting directives, and two enemy-buffing directives - as well as fog of war, which stays consistent).
If you look in the summit you'll see the full list, but in the open world and missions they limit it to five each season.