Now culture system promote only rushers who skip star gathering to pick up best culture. It's not that bad for balance control, but it's annoying to play with sometimes and just not much immersive. I was shocked that game don't even got achievements as "simulate historical "cultural" evolve of" (for example) French" where you have to play as Celts, Franks and French in one game.

Maybe if game gives us something like:
- 5 era stars - Can only stay culture that we are now
- 6 era stars - Can choose only from 2-3 cultures closes to ours
- 7 era stars - Can choose from all cultures type of our own
- 9 era stars - Can pick from all available cultures

Maybe some stability penalty when converting to more distant cultures to ours, maybe some culture influence shift.

Big culture shifts would be rarer, player and AI would be more constant, and it would help immersion, as I would gladly see Romans to evolve into Byzantine/Franks and over time to Italians.

And maybe even something different from that like
hard cap of stars would be the same, but you can only change to culture from your own type (European, American, etc) and gain ability to change for other if completing something big like conquering another nation or a whole continent, or settle to another continent, or even been culture dominated by different type culture gives you ability to pick type similar to them. Make culture shift more story dependent, I think that rush or picking what's left is a such immersive breaking thing.