I wasn't referring to just prejudice, but also interests, Nicolau is still a good example as he considered a national hero while being ignored for promotion at the same time, because the European officers were usually favoured over those born in the colonies, the nobility and the clergy will never accept to share the power, unless they are forced to do it, look at the Porto Rebellion, the Liberal wanted to end absolutism and impose a Constitution on the Monarchy, a Constitution that was considered very innovative for it's time, but not even they, which one would assume would be more willing to compromise with Brasil, were willing to accept the post-Napoleonic reality, that Brasil was no longer a colony.
Best it would happen, as I said before here, would be a nominal subservience of Brasil, a Dominion relationship is you wish to call it that, that there wouldn't be one parliament for the two Kingdom, there would be one for Portugal and another for Brasil, and after the 1860's, when Brasil's population is double that of Portugal, this would be even more nominal than before.