During a Long Reflection period, another idea is to treat utopia similar to a git worktree. Branch different versions of utopia, try out variations on branches, and then merge the improvements back to main. The software analogy also implies merging smaller, modular changes frequently to avoid branches growing stale/incompatible. Each change would need to be justified back to main through a PR process. To avoid falling into local minima, we would need to refactor incrementally, borrowing something like the Strangler fig pattern.
I'd contrast this with the archipelago setup, which I view through the software lens as creating a diversity of less related apps, which would likely diverge significantly over time--trying to merge a full archipelago would create a conflict. But I don't think these two views are necessarily mutually exclusive. For instance, you could apply the worktree structure within each island of an archipelago.
Something like this was mentioned long ago by Paul Christiano in the original ELK report, as a possible outer alignment target. (See the indirect normativity section on page 62). It solves the issue where we need to delegate to some state to move utopia forward, but need information from other branches too.
What makes this better than a federal republic like the US? States can experiment with different laws and ways of living, good ideas can be adopted by the federal government if the rest of the country likes them. “Main” is just the federal government and the rules and cultural patterns that reach everyone.
I feel like the main advantage of your idea is the implication that we can regularly spin up polities to run better experiments. I agree this would be useful, but technically a federal republic can do that too, it just needs new land (space colonization) on which to do it.
It seems to me that basically the whole problem is determining what we should be aiming for. The idea of "merge in any improvements" doesn't help unless we already know how to define "improvement".
The standard motte-and-bailey is framed as a move on the part of the party making the claim (let's call her Alice). But I think things that look like a motte-and-bailey can often be the result of the conversational partner (Bob) not making it safe for Alice to concede that her original point was fuzzy or too strong. If Bob will treat Alice's updating/saying "You're right, my claim is too strong" as proof of lower status, then the motte-and-bailey move (to backtrack and state she was not trying to make the stronger claim to begin with) becomes much more available and attractive as an option, as it lets her save face/keep status.
This predicts that we would see more motte-and-bailey dynamics in adversarial public discussions where the outcome of the debate amounts to an exchange of status or power, and should be rarer in cases where status is already settled, or in high-trust environments.