I'm actually skeptical you can do it much earlier. Take New England, for instance. People were aware something was this since the 1490s. Yet there was no settlement until the PIlgrims. Why bother? Europe had furs and fish of its own.
Well, yes, but as soon as there was a basis for further settlement (as opposed to jumping into the wilderness) immigration became extremely consistent. I would argue that what was really lacking was a starting point to provide security; after that people became willing to make moves for religious purposes or otherwise. I don't think you can get settlement much
faster though, once it starts, and the earlier it starts the fewer will be coming.
It may not be what you mean, but I do think that an earlier cotton gin would have this result. It created a vast labor shortage in the colonies, exacerbating what was already there. Since wage labor wasn't really a factor and indenture was unpopular, it isn't likely to change much in terms of European settlement, but it would increase the value of slaves relative to the Caribbean. Over 50 years or so, that would mean dozens of slave ships sailing north to sell cargoes left-over from the Caribbean markets. And while slaves in the Caribbean were usually dead inside 5 years, those in North America would regularly live long enough to raise a family.
End result: A much more heavily settled south (the difference being all black and mostly slave) and a
slightly more settled north (more slaves to go around means more up north, eventually).