Looks like a chink in the Brazil visa "armor".
More exceptions will come with time
from those who have the knowledge,
one or more of which may apply to my itinerary:

"...you can get into Brazil without a Visa is if you are on land, coming over from Guyana. If you get to the border town of Lethem, you can walk across the bridge and the border guards will let you go over, get a lunch and spend a few hours, but you must walk back over to Guyana by the end of the day."

Odd, how resentment is stirred up in those who obediently paid
without doing research on possible money-saving strategies.