Food would be the big thing I'm guessing, no animals to prey upon. Will animals get more chances to respawn?
Then there's biome specific stuff. As far as I can tell the generated world is limited to a single biome. Is there a certain one needed to fully flush out the tech tree? If not, what would be the optimal biome to make the world? Gil pointed out in IRC that I'd need somewhere wolves can spawn.
Here's the code with biome features and villages turned on, as well as less glass than compared to the video
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2;7,49x20;1;mineshaft(chance=0.2),dungeon,decoration,lake,lava_lake,stronghold,biome_1,village(distance=50)
Any other ideas for taking advantage of the superflat custom generated worlds?