It's possible but iffy with the Fulmen Nati. They are perfectly open to the existence of gods and pantheons other than their own, and they are also open to the worship of aforementioned gods and pantheons. . .Just so long as THEIRS come first.

Between the Hallucinogenic Incense, the rather well-educated Priesthood, and the fact that literally 100% of the population is Effulgent - it might be difficult to cram in a weirdo mini-pantheon with only one major god that doesn't carry any of the same perks worshiping the native religion does. I am open to suggestions though.