Thanks again for your thoughts. 4 decay is a bit much, I agree. I would prefer running a second force of vigor over the fourth copy. Its just that this deck struggles with overcoming Oko, and I expect to see 2-3 oko-decks in my small meta. I don't really see trophy as an alternative. Decay hits almost all the same targets and is, in my opinion, a far stronger maindeck card: Game one, control opponents can easily be holding dead flusterstorms or forces of negation.
When thinking about it, this is a reason to reconsider gsz. The inclusion of the card is most strongly motivated by the possibility of finding hate turn one: Reclaimer against HollowVine (to find tabernacle) and Dryad militant against Breach. But HollowVine runs forces of negation and Breach runs flusterstorms, and it could be a bad idea to make those cards useful against me.
Dryad militant is untested, but it is 1cmc and green, to make gsz with x=1 turn one a strong play against Breach. I need to play enough games against Breach to find out if I can rely on it. If dryad militant does not prove to be good enough, I will consider cutting the whole gsz plan. Canonist is a phenomenal card, but I doubt I will make room for it this time. I much prefer Tabernacle against HollowVine and Dredge and have sufficient incidental hate, plus a Karakas, against oath. How is canonist relevant versus Doomsday?
Yes, Knight is an allstar against Eldrazi, while questing beast is probably just trading in that matchup. I also don't fear Eldrazi much. (I hope to not have to eat my words later, but this deck should run circles around eldrazi. I'll side out a bunch of cards against it, so having cards to bring in is nice.) Questing beast could be good against various control decks with planeswalkers. I hope I get to test it enough to know if it's good.
Once upon a time is fantastic in this deck 🙂 It's utility grows with every narrow or situational creature and land in a deck, and this has very many of those. I play only 3 to avoid drawing more than one at a time.