Because of world market and constant mechanics shared by all the POPs in the game the growth rate is deterministic no matter what. However it is initially set will be off at some point. Compared to V1 I would prefer to see slightly slower growth at the start of the game and technology and infrastructure increasing growth so by the end world population would probably end being higher than historical almost guaranteed but would vary more by country and the overall population wouldn't be surpassing historic levels until after 1900 at least.
I remember playing Italy and achieving 500 million Italians by 1900 with high plurality and force migrating POPs to highest life rating provinces. That is of course unrealistic in more than just the % growth rate we are talking about but the only reason I even bothered to attempt it was due to the high % growth rate making it worthwhile.
Trying to model realistic curves without actual input on what V2 uses to determine growth rates might be futile. Probably the easiest way is to use technology to speed up growth even though all historical data available points to a correlation between income and pop growth rates. Anything else is likely to lead towards backwards game play as people attempt to max their % growth rates.
I have tried something with my calculator, to have the historical growth rate of New York City, it would be on average around 42% per 10 year.
I think most are immigrants because 42% is just absurd...