Lingua Franca

I´m pretty sure this has been treated before but...quechua, nahualt, lingua geral amazonica, lingua geral paulista were linguas francas that may have survived until now but that were swallowed up by the Castilian and Portuguese. My question is:
How you could make these languages survived until today? What might have meant for these areas? Is an ASB theme to imagine two Brazils by that?
 
Don't forget the original lingua franca itself. Any of these lingue franche might have survived in a limited area, but you'd have to have a major POD to have them retain prominence.
 
Is the easiest to keep alive. Just have Portugal recognize it as an official language.

Easier said than done. I don't think an imperial power in America has ever recognized an indigenous language as official, unfortunately. However, there may be some circumstances by which small pockets of speakers remain. It all depends where the OP wants to have it remain the lingua franca or simply a living language.
 
The past of these languages, at least the two lingua geral of Brazil, seems quite attached to the Jesuits. Could these languages survive with a better relationship between this company and Portugal?
 
Moreover, we found the problem of independence. Let's say that the independence of Portugal is carried out by Republican means and a war of independence against the metropolis around 1800. These authorities would be more prone to the survival of the lingua geral or for that time was too late?
 
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