So I happened to browse bay12 for a bit today and I noticed that Paradox is using an at least superficially identical espionage system to the one I developed for Axioms Of Dominion. They even use the word Secrets in an identical way to my system. Of course the scope of my game allows for way cooler secrets.
https://axioms-of-dominion.fandom.com/wiki/Secrets
And there are other functions that Paradox doesn't have the creativity to come up with. But still. Only took them 7 years to debut a concept with nearly identical functionality, for what functionality they have which isn't much, and an identical name. Granted the name is one of 4 or 5 "obvious" terms to use but still. Give them 10 years of DLC and they might get a system as detailed and nuanced as Axioms has/had.
Edit: I see they also have a system similar to my Government/Treaty/Charter system, although again in a massively scaled down way that suggests it is a placeholder for a system that is actually cool, called "Feudal Contracts".