One solution may be to request a VIPER (VIsto PERmanente, Permanent Visa) (which at first is actually issued for 2 years, after that time you need to apply again to make it properly permanent). It seems to be a lot of hassle though, including transferring some amount of money to a Brazilian account every month, getting an RNE (Brazilian foreigner ID). Several years ago it took me over 4 months to get a VITEM V (temporary working visa), so I can imagine it takes even longer to request a permanent one.
It appears that I would have to apply for permanent residence, and then just leave when I am ready. (…) Would such a cancellation prevent future visits?
I can’t find a definite answer (in English or Portuguese), but I know plenty of people who got permanent visa / residency (e.g. because they married with a Brazilian), left the country after several years and kept coming back as tourists. After all, your plans may change.
This article about VIPER on the Consulate General of Brazil in Vancouver says:
If the holder of a permanent visa, even after all registration procedures in Brazil have been completed, leaves the country for more than two years in a row, the visa will expire, the ID for foreigner (RNE) will automatically be revoked and the person will have to re-apply for a new permanent visa.
It seems to be outdated though, e.g. it mentions at least R$6.000 (~1.100 USD) monthly, but this decree issued by the Brazilian MFA in 2019 says (link in Portuguese, translated by me):
Art. 1º The temporary visa can be issued to a retired immigrant or a pension beneficiary, who can show a proof of a monthly transfer to Brazil of 2.000,00 USD or a higher value, in a foreign currency (…)