I have no clue if this exists, but if so I haven't been able to find it.
basically I'm taking the concept from the mod "Darth-mod ultimate commander" for the game "Empire total war".
fans of the mod can freely make their own/ publish their own "mini-mods" that people can play as an addition, afterwards the devs can take these mods freely but have to say where it came from... that way, people can make their own ideas and make them public, and some can even go in-game. it will make the wait a lot less agonising for SP players like me; and will be another source of creativity
eg:
Random dev: "what you have a great idea? well, do it, publish it, let people play it, see if they (and we) enjoy it, and we might put it in-game. (without doing much work)
I think this works in everyone's favour.
LIBERTY IS THE STRONGEST OF THEM ALL!!! oh wait, that's 4.84
Now you'll see. I'll predict the future. in 4.86 Gallia will launch a full scale attack on the houses! guess how I know.