Considering some independendist movements and revolts OTL, before and during the Regency period, I will bet in those two things:
1 - The Revolutionaries would be Masons of Liberal/Republican/Iluminist ideals (like the revolutionaries in
Minas Gerais, 1789 and Pernambuco,
1817/
1824), the poor and futigived slaves (like what happened in Grão-Pará during the
Cabanagem (1835-40) and in Maranhão) and middle-class ranchers (like the
Ragamuffins in Rio Grande do Sul and the
Balaios in Maranhão). Let us not forget that the revolution would also have a strong religious character, like in Mexico. The Cabanos in Grão-Pará claimed to be defending the Catholic faith and the Pernambucans Revolts had a strong participation of the Catholic clergy.
2 - As the provinces of the North were more dependent on slavery (although it was also declining at the start of the XIX Century together with the production of cotton and sugarcane) the revolts there would be composed massively of slaves and poor people against the landowner elite. The leadership would be composed of enlightened men like Antonio Angelim in Grão-Pará OTL and the Masons in the two Pernambucan revolts, both as it happened OTL. A mix of Haitianism and the American Revolutions basically.
3 - The South, however, had a small slave population (although this would change with the introduction of coffe plantations). The Revolts there would have less en masse popular support than in the north. Also they are quite distant from their neighbors close to the Equator. For example: During the War of the Independence the northern provinces sided with Lisbon because they had closer relations with them than with Rio de Janeiro. So we could see two confederations forming in the best scenario. In the worst we will have splinter republics.
4 - Then we have Rio Grande do Sul: Its etno-cultural life was closer to the Platinians than the Brazilians, with whom they had close economic ties. The economy was basically pecuarist. OTL they revolted against the Empire of Brazil due to high taxes and excessive interference of Rio de Janeiro. A union with Uruguay (which would never be invaded in this TL). They could also revolt against the Portuguese Crown or a Southern confederation as OTL.
5 - Independent of how this would affect the Brazilians, the Platines would surely benefit. Without a Luso-Brazilian invasion of Uruguay we could have a victorious
Liga Federal, which is a must-see.
tl;dr: Abolitionist, religious and turned-to-the-middle class Republics in the North and more Elitist and "vanilla" republics in the South. Rio Grande do Sul independent and in the Platine sphere. Using this map as an example we could get:
1.
Grão-Pará probably independent
2. Maranhão and Piauí could form a republic, most probably would go to the Confederation of the Equator
3. Ceará, RN, PB, PE and AL:
Confederation of the Equator
4.
Bahia probably independent or part of the Confederation
5. Southern states:
United States of Brazil
6. Santa Catarina and Rio Grande do Sul (that wouldn't have those borders since the United Kingdom of Portugal, Brazil and Algarves was butterflied away and together with it the Luso-Brazilian invasion of the Banda Oriental, see this other
map for reference):
Free Republic of Rio Grande de São Pedro. Maybe it would ask a Platine federation for annexation.
7. Cisplatina: Never conquered. Seat of power of the Platine
Liga Federal.
Sorry for the wall of text.
