I really like the game rule feature, and after noticing that you could look at it from the culture/religion info screen, I realized that it might be convenient to change certain game rules mid-game.
The primary one I'm thinking about is the conclave education notifications, where, when you're a count, it might be feasible and even advantageous to micromange the education of every child in your court, but which gets extremely tedious as a king or emporer. The ability to change this rule mid-game would be nice, and changing this rule mid-game would not provide a major advantage. If you're concerned about people cheesing it, you could always make changing game rules break iron/bronzeman games. There are probably a few other game rules in a similar situation, but the conclave education one is the main one I thought would be both useful and not game-breaking.
TL;DR: Let us change our education pop-up game rule mid playthrough.