I don't think comparing Aztec to Korea in that way is charitable.
Persia is the Golden Ages domination civ
Brazil is the Golden Ages CV civ
Korea is the Golden Ages SV civ
So what does Aztec do? They have more and earlier faith than Korea. They have more golden ages than any of those other civs. but their biggest difference is they have more food, and more hammers than any of those other civs, and the consistent golden ages means they have a steady supply of money for investment. This makes a lot of sense, considering the size of Tenochtitlan, and the enormous population that the Aztec Empire encompassed. So I think that merely a little more food, and a little more hammers is all that's needed. That high production and population can help create a massive war machine, but you could just as well pummel a pet civ for free GAs, and focus on a "
build ALL the things!" style
How about +15%

, +20%

, +35%

in all cities and +1

to all gold tiles for 10 turns after winning a war?
That proposed +15%

/

to the UB during GAs is more than enough I think, and it will be useful even if you don't go for a hard domination with Aztec.
I edited the thing you quoted. Of course an elimination should be attractive, but the benefits of winning should be attractive enough that a mere win should placate you, rather than going for the more tedious elimination.