So, I've always found these maps great fun in Civ; it adds an extra early/mid-game race and can mix things up with new neighbors, not to mention giving you a reason to build and research boats.  However, in Humankind, the AI seems very, very bad at this.  In two games now (first on Metropolis difficulty, second Nation), I have claimed the entire New World continent before any other faction even discovers it.  I have a few suggestions:

1. The tech that makes new cities start with all the Era I-III infrastructure is ludicrously overpowered.  Just indescribably overpowered.  The city pops out of nowhere and is almost as strong as your original cities (less population but far more infrastructure).  This includes instantaneous fortifications.  Needs to be tuned way back, like giving you the choice of maybe three infrastructures to start with instead of 15 or whatever.

2. I come into the game with meta-knowledge that another continent is out there.  The AI needs to behave the same way.  The AI factions should prioritize finding the New World, as long as their situation allows it.  At the very least, your trade partners should discover its approximate location not long after you do.

3. There need to be a lot more established independent peoples in the New World.  Would be historically accurate as well as make for a better game.  If you're roleplaying, you will have some interesting choices as to how to deal with your new neighbors.  They ought to be quite a challenge, and not too pleased with the invaders (you).  As it is, an occasional mercenary band pops up, but it's usually from a nearby island.  I have yet to see an independent city or outpost in the New World.  Progress colonizing the new continent should be very slow, not a steamroller.

4. More dangerous/impossible sea voyages.  Obviously this is what delayed colonization of the Americas historically.  As it is, it is not that hard to cross the unusually narrow oceans in a quadrireme.  Especially if you have bonuses to naval movement (Lighthouse of Alexandria, etc.).  There's also no risk at all; you can venture out one turn's worth of movement, and if you don't spot coastal waters, come right back to safety.  There need to be some storms/random disasters at sea in the very early ages that can sink your ships without warning.

5. This isn't a suggestion, so much as an observation.  In the first game, I got what seemed to be a scripted event based on era progression that basically gave me a choice to fund an expedition to find the New World.  But this happened decades after I had already fully colonized it.  Hm.  This makes me think that the devs have seriously underestimated the speed at which a player can go find the New World.

Oh yes the colony packages are absolutely busted, I went french industrialists and rushed the modern colony package, burnt down my small cities and rebuilt them with modern builders getting everything for free. Everytime I do a new world settle my new world city always is considered my 'best' city at the end of the game.

To get a "proper" New World experience, you have to set the land percentage to 50% or less, regular spacing between continents, few islands (to prevent island hopping), and maaaaaybe a larger map (I haven't tried it with smaller ones, but it could probably work with the other settings I described). That way the empty continent is locked behind Three-Masted Ships (or Seafaring Mastery for Norse).

In any case though, it would be nice if we could get a "colony" mechanic that played differently than cities. Maybe something that works like a vassal? I tried to test it by releasing one of my cities, but they just become neutrals, with a mere 50 points relationship bonus with you.

I think that the city limit is waaay too large and contributes to the snowballing effect the game has. Lowering that limit and giving us the ability to have puppet city states under our rule that provide a fraction of their resources would be a nice way to allow expansion without making you too overpowered.