Regardless, I dont know that now is the time for more than 60 cards, but I do know that as the card pool expands, it gets easier and easier to find more spells of a similar power level, but no other lands are close to the power level of fetchlands, so the incentives to build to maximize the power of our lands over the power of our spells do increase in some way over time, which is to say that, even if its not right now, it could be someday, and getting there first might be the best way to truly break Modern.
Best per-pack value
Since the Dragons mode only cares about creatures leaving the battlefield instead of dying, some sneaky flicker and ninjitsu tactics can make Outpost Siege better than average
When you cast the card it moves to the stack and is no longer in the zone you cast it from
However, when it is taken as a prize card, players can immediately place it on the bench and flip a coin