Hi! I'd love to hear your feedback on this idea. (Tech & Res 1.2)

In short, I don't like how population in 1.2 works, despite all the triggers, events, and changes in the definition file. In 1880 and 1930, population growth seems to slow, but after 1890 and 1940, new medical-related events keep it high. But at least it's better than the vanilla game.

- The "vanilla" SoL curve for population growth is too high, and rich countries experience exponential growth until 1970, especially European ones, while poor countries continue to grow slowly (India, China, Brazil, Indonesia), reaching too fast an high level of SoL.

- The "Tech & Res 1.2" SoL curve for population growth makes things more realistic: the behavior of rich countries is actually very good, while poor countries grow faster than "Vanilla," but not as fast as in the real world (India and China do +4M in the 50s, in the real world +15M). Brazil and Indonesia have a small buff.
And then there's the real problem: semi-rich countries, those that, due to the AI's stupidity, always stay around 20 SoL throughout the game and their population continues to grow exponentially. (This often happens with Spain, Austria, Belgium, and Russia.)

The problem is simply that Vic 3 SoL is unable to simulate population growth after 1930... and rightly so, it ends in 1936.

Theoretically, the SoL is proportional to pop growth until the SoL is less than 12/13.
- The mortality rate drops until 12/13 of the SoL, then flatlines (as in Vanilla), but over time it can only decrease thanks to technology and medicine. (As in Tech & Res).
- The birth rate is the most problematic, because, after 12/13 of SoL, it should no longer be inversely proportional to the SoL, but is inversely proportional to a counter that starts, for example, with a bonus of +40% births.

This counter advances over time based on factors such as:
1. Time (How many years since you reached 12 SoL)
2. SoL (Obviously, if it is high, it accelerates the process of birth rate declining)
3. Literacy (Accelerates the process)
4. Immigration, slavery, and multiculturalism (Slows the process)
5. Autocratic/oligarchic governments (Slows the process)

The further it goes, the lower the birth rate. Therefore, even if you're Spain, Austria, or Belgium and you reached 12 SoL in 1870 but still have 19 SoL in 1970, your birth rate is low, not high.
For example, countries like the USA, which had 12 SoL in 1850, will theoretically have a high birth rate in 1970 if they've been feeding their population with immigration during this period.

It might seem confusing, but shifting the question from "How much SoL do you have?" to "How long has it been since you passed SoL 12 and what have you done in the meantime?" It is the only strategy to create a realistic population boom window after which there is a decline.
Actually, this method is much less game broken and controllable by the player than Vanilla SoL one, which will remain but will be a little less relevant.

This in the game would be simulated through a semi-hidden journal entry that updates itself each year based on the factors previously listed.