Would such a project be particularly volume constrained?
> doubt democracy would get them through more than 250 days, let alone 250 years
I don't. You'd be selecting for extraordinary individuals and educating them. These sorts of societies propagated for hundreds or even thousands of years in antiquity just fine.
The colonists be in a life-or-death system in a community small enough that everyone knows of everyone else personally. To the extent humans are almost uniquely exceptional at one thing as a hominid, it's exploration and colonization--I woudn't be surprised if this group winds up more functional due to scratching an underlying human need to explore and push boundaries.
As for democracy "These sorts of societies propagated for hundreds or even thousands of years in antiquity just fine" - I don't know of any that practised the consensus driven democracy that almost all these proposals use. Ant if you're reaching into antiquity then not even normal democracies. Unless you're talking about a Athens with their slaves and adult male citizen population having a vote. In which case sure, I can get behind that but that's not what those spaceship designs propose. They all assume all decisions will be unanimous and no one will ever break the law.
In actual fact history proves the opposite and all exploration and conquest is driven by strict hierarchical organisations and the idea that you can fly a spaceship across light years without a captain who can condemn people to death is laughable.
Love the designs, doubt democracy would get them through more than 250 days, let alone 250 years.
1m is not a lot
Edit: as per my comment below, casualties are not deaths. It's a wider definition.
I think I'm on safe grounds calling it a walking simulator. The gameplay is limited to walking down a linear path and clicking on things until all combinations are exhausted - western equivalent of a visual novel (but with less branching).