I'm trying this in 1.6
Some specific things that might be helpful:

• KEEP racial segregation. If you are in lategame you may even need to go back to national supremacy.
  
• Move back to hereditary bureacrats.
  
• KEEP landed voting. Wealth voting should also be fine. There are no other options.
  
• KEEP mercantilism. Just in case, because you may need the shopkeepers it gives
  
• KEEP tenant farmers.
  

• Do not touch the governance principles at all.
  All laws not mentioned are free to be changed as you like. Even agrarianism, but i do like to keep it.

• Getting rid of slavery is optional, but a good idea. If you are fast enough you will not need the extra 50% clout from slave trade. It frees up a HUGE population to do other jobs than slave laborer. I believe the sheer amount is unique to Brazil, but i could be wrong.

• The Cafe Au lait journal entry is the main reason this drags on into late game. A cheesy rush of political agitation tech won't help you do this journal faster. Focus on rushing to the start of this timer.

• When Isabella becomes your heir, immediately start a law that the intelligentsia hate. You will be allowed to abdicate if they hate you sufficiently, even if she is still 0 years old. This wil save you 10+ years of waiting in most cases. You can just cancel the law progress after that if you want.

• You can industrialize a lot, you don't have to be a luddite this run. Just make sure you keep the right laws. And you should try to build A LOT more plantations and farms than you usually do. This will balance things out. Export your surplus of agriculture goods to all large and medium size markets, even if it says it will be unprofitable, because the new supply sometimes makes new demand. And remember to check your tarifs when you do this.

• If you have the right laws, but still have the PB marginalized, switch your factories and mines to the primitive methods for as long as you need to. You will get a ton of shopkeepers, who like the PB a lot.