I find the whole Native Policy screen to be problematic, not for the idea, but because it doesn't reflect the actual policies used at the time. Especially the coexistence one.
- Trading is useful for representing colonial empires based on trade routes and tariff output efficiency, like New France, Canada and Louisiane, or early Portuguese colonial empire.
- Repressions might represent English settlement, which actively drove out Natives and relocated or exterminated them, but nothing else.
- Coexistence is total fantasy. No European colony ever tried to peacefully coexist with the Natives completely. There was always subjugation (Spain), war and annihilation (England) or unfair trade conditions (France and Portugal).
And still there's no option to reflect Spanish colonization policy. I think it's easy to change these options into these four:
1- Proprietor/Encomienda.
----- Colonists are given land and natives to work the land, and they give production benefits in return. They also demand great autonomy. It's basically a Feudal system but in the Americas. The Spanish way. The idea is that colonisation can be super hard to manage and rule, so the colonies must be semi-autonomous at the beginning. Changing the system into Plantation or Population takes time and effort, and would only be possible in the early 1600's. Spain tried but never could, even in the 1720's, and alienating the criollo aristocracy only helped fuel the Latin American revolutions.
----- + stability, - - liberty desire, but average to low gains. Extra gov points? (For the lack of actual governing)
2- Plantation.
----- The focus is on production, regardless of native lives or even colonist input. This is the system that the Portuguese and most of the Caribbean colonies developed.
----- + production and benefits, - gov points (all that governing and taxation is hard), and there's also the need to import slaves, but I doubt Paradox will model the Triangular Trade into the game.
3- Trade.
------ The focus is on getting valuous products through unequal trade with the Natives. They're happy to get trinkets, guns, clothes and other manufactures, and you're happy they're giving you all that timber, silver, etc. This system can be very stable but it's not strong when it comes to war against other, more populous colonies or even Indian nations. But you can use Indians to fight your wars!
----- + trade output, - immigration, + stability. ++ diplo with Natives.
4- Population.
------ Here, the colonies are mostly a dump for your population excess (at first, anyway). Vicky engine would be perfect because it did just that, but EUIV doesn't have PoPs. Anyway, immigration can be modeled with just math and coding magic. The idea is that the metropolis wants its population excess to stop lazying around and doing bad things (like heresy) and go work and be productive in the colonies instead, where their criminal ways don't matter and where their heresy doesn't fall into the ears of decent people.
------ + production output (in time), + immigration, - stability, - - diplo with natives. The more population you get, the more benefits, but also the more liberty desire they get.
- This is, of course, the model England followed.
All this models have short time benefits (mostly, the chance of having a colonial empire that doesn't cost much but also doesn't do much), as well as long time ones, which come at a risk. The only ones that don't post a risk at long term as the ones that provide with stability or that are easy to establish (Spanish model and French model). Meanwhile, plantations are beneficial for trade and production but costly in gov points, while population colonies are slow to grow, very beneficial when they're big but very volatile.
This is the way I would have done it. Less arcade than Paradox devs and more historically guided, but maybe I'm missing something important. I'm not a game designer by any means.
No migration to neighboring province? No wish to settle within the colonial province (may be adding a little bit economical boost to province) - just gone?
