As title says, Titania's Dex Pixia and Diwata can trigger the effects of primary arcanes despite being an exalted weapon, and not a primary one.
The ones that worked where
-Primary Blight (Bonus applies to primary without needing to mod for toxin)
-Primary Frostbite (Bonus applies to primary without needing to mod for cold)
-Primary Exhilarate
-Primary Obstruct
Since I don't own Primary plated round I couldn't test it