I think Brazil is a location suited only to the Japanese trying for an economic victory, and at that it is something that can sort of be smelled out in advance by the Americans.
I am on the side of those who argue that the EUsa can and should be the embarkation point for those forces going to work in Africa. Brazil is something of a secondary point; it’s real value is realized when the Axis take it, but this can easily be countered by the US sending a few INF down there.
Rather than mess around with Brazil, I would advise the US player to simply get transports and then once enough of them are built get a few escort vessels to forestall any air attacks on your convoys and hit Africa from East USA.