How has the testing been going with this? Have you tried using Ritual of Soot in the build? It's sorcery speed, but helps clean any slower starts.
I'm really liking Carnage Tyrant as a primary win condition in MTGA. When I play control I get like 70% control mirrors, and Carnage Tyrant is AWESOME in those games. Some decks like Izzet have almost nothing they can do about it if they aren't running a creature-based deck.
@achilles Also forgot to address the other part of your question - I stopped having issues when I made sure to always interact with my opponent first, and leave azcanta for later, like on turn 4, when I can still play another 2 drop interactive spell.
@alechilles The only match-up I found myself always wanting it was in the tokens match-up. But as I expressed, I fear that a good tokens opponent just needs to cast march of the multitudes to play around the ritual. This is one of those picks where I'm willing to say that I might be wrong about not running it in the sideboard at the very least.