This is why starting in the northern part of the hemisphere matters so much; if explorers unexpectedly run into the American continent there, they won't see this new territory as something that has to turn a profit so soon to justify themselves to their royal backers, since they're naturally expecting the real return on investment to lie further west.
The Portuguese did not discover Brazil to find a different way to the Indies. Even if the first discovery takes place in North America, you already have the Iberian powers interacting with the African coast, exchanging metals, tobacco and other things in exchange for slaves and products such as ivory. The colonization of Brazil did not take place through gold but through the paubrasil wood used for dyeing. In North America we have furs among other products. If, for example, England discovers North America and sees nothing of value in the region and gives up on the continent, there are still the Spanish, Portuguese and French exploring
And by the time they do find the caribbean, nobody's expecting settlements on the island to turn long term profits, so any "conquest and plantation" ambitions that emerge will be pretty small scale compared to what Columbus managed OTL,
People who take these trips are exploited with usually no morals, coming from nothing and wanting to get rich. The Portuguese acted like vikins or pirates in the indian ocean because the members are not nobles but poor peasents with nothing to lose. If, for example, the conquest of the civilizations of Mesoamerica and the Andes does not occur. The Caribbean is easy to colonize as well as the coast of Brazil. Both have valuable products. Even if the production of sugar takes longer to occur, it will occur because all the factors for its creation are there.
and likely won't develop the same "demand" for" imported labor" to nearly the same scale that OTL's caribbean colonies did.
I honestly don't see how you have the sugar boom in the caribbean due to the colonization of brazil which developed good techniques in sugar production and after the invasion of the dutch this in turn brought the techniques to the caribbean (this literally caused a mini crisis in the Portuguese colony).
Christopher Columbus, introduced the planting of sugarcane in America, on his second trip to the continent but the Spaniards discovered the gold and silver of the Aztec and Inca civilizations, in the early 16th century, the cultivation of sugarcane and the production of sugar were forgotten. In 1532, the first sugarcane was moved to Brazil, in the northeast of the colony where sugar mills multiplied. After several difficulties, after 50 years, Brazil began to monopolize world sugar production.
Portugal and the Netherlands, which marketed the product, had high profitability. Europe, enriched by gold and silver from the New World, became a major consumer of sugar. In the year 1578 Portugal was annexed by Spain. The Spanish king, Felipe II, a fervent Catholic, was bitterly opposed to Holland and England, Protestant countries. Dutch trade collapsed and in 1630 the Dutch invaded Brazil, remaining in Pernambuco until 1654, when they were expelled. To reduce dependence on Brazilian sugar, the Dutch started sugar production in the Caribbean and later the English and French themselves did the same in their colonies, ending the monopoly of Brazilian sugar.