@Kenraali Your best bet is probably the Fractal landmass, which is one of the choices for the Continents Landmasses option. Unlike Continents, Fractal does not try to force the size of two continents to be roughly equal, so with perhaps a few re-rolls you might get that big continent + small continent combo that you're looking for.

If you want bigger continents then I suggest lowering sea level, although that increases the odds of continents merging into a pangea shape. Another approach would be to use a larger map size and/or fewer players on the map, so that the larger continent is large enough to fit all of major civs.

Hope that helps, and good luck!

Also a quick question - how can I make minors start in the new world AND in the old world? I get how Largest Area for the land starts makes majors start in the Old World, and then picking Standard for the minors would make them start in the Old World as well, right?

Apparently, that does not work. They so far have ONLY started in other landmasses. And reading the descriptions for other options, they would not work with my wishes.

You can try setting minor starts to Major Areas, so that the minor civs are treated like major civs but without the restriction of starting on the largest continent. That will at least discourage the minor civs from starting on tiny islands or other places that major civs normally wouldn't start on, so that there are fewer alternative starting spots for minor civs.

Another challenge, however, is the that your old world might already be too crowded with major civs to fit any minor civs. You could reduce major player count and/or increase city state count to see if that allows the script to cram some city states into the old world. But if the map gets too crowded for your settings to work then the script will fall back to regular starting rules instead of your choices for major/minor starts.

Even if the above suggestions work, keep in mind that having city states in the old world probably means that the new world will be just as crowded with already-existing cities by the time you cross the ocean.

After generating a few maps, I think it wouldn't be out of the question for me to just...request you make a Continents option similar to this? 2 major continents, one smaller (roughly 8-10% of the total land mass) and one bigger (roughly 55-60%).
Because I also don't really like that the YNAMP Terra forces you to use it's map sizes - not the official ones. I might've missed a few achievements because of that.
Or could you tell me how to edit the Lua file so I can do it myself?

This is technically doable but would be a nontrivial update to Got Lakes. Perhaps instead I might make something like this for civ7 sometime next year.

Most unfortunate. I myself am skipping Civ 7 for now.
But regardless, thank you for your hard work for making a good map script.