“The ARI HaKodesh instituted Nusach Sefard. I would take the AriZal anytime.”
Where is that written?
AFAIK, he used what was the Mesorah in Egypt and E”Y at the time – Sephardi. He provided incites into the deeper meanings and Kavanot, but he did not write a new Siddur. If I’m wrong, please provide a source.