I think that kind of draw engine only works in stax-style or heavy permanent decks where you want to play out all your cards immediately. Your cards disappear if you don't use them under Uba Mask, so you don't get to hold onto instants. I suppose the deck could be reworked heavily, or you could do Sylvan+Abundance. Mask is certainly a lot more disruptive which probably makes it more worth the 4 mana.

Wall of Omens could be interesting, except for the deck's reliance on Humility.