IMHO, governments have immune systems. If you try to set up something that is too directly in conflict with what the broader culture is already doing, then the immune system triggers, and the authorities will try to quash you.
This is something that I fear will happen with the seasteading project in French Polynesia. The success of the project depends on the cooperation of both the French government and the local French Polynesian government.
So far, TSI/Blue Frontiers has done an admirable job of not triggering the immune system of French Polynesia nor France.
However, I wonder how much of that is a function of the fact that they've not yet defined what it is that they will be allowed to do.
For example, I could see the existing hotels putting up a fuss if they try to get special tax privileges for the seazone. Local construction firms might try to block immigration liberalization, since that would mean seazone members could hire (less expensive) laborers from outside of French Polynesia.
If the project does get bogged down by such an immune response, perhaps a "discreet Free State Project" strategy could work instead.
You pick a state like say, Panama. Panama already has several desirable features relative to French Polynesia:
hub of international trade and finance
relatively liberal already (prostitution is legal, drugs somewhat tolerated)
easy visa / relatively easy immigration
low cost of living
Eastern time zone
easy/cheap flights from U.S.
low hurricane risk
close to many other lovely countries (Costa Rica, Colombia, etc).
fast internet
Spanish language second most common in the U.S.
With four million residents, Panama is large enough to support a healthy economy, but small enough that a relatively small group of people can have a disproportionate influence.
According to academic research, it only takes somewhere between 2-3.5% of the population becoming activists to stage a successful non-violent revolution. For Panama, that would be somewhere between 80 - 120 K people, roughly the same population of Boise, ID.
So, start a small floating "planned community" in protected waters off the coast of a beautiful beach. Bocas del Toro, let's say. Let's call the community "San Bastiat".
Don't advertise publicly. Don't try to change the government at first. Say nothing that would trigger a politician. Blend in with the locals, learn Spanish, become a citizen, make friends with the local politicians.
Only invite friends, and friends of friends to buy in.
In private, pitch would-be residents on the idea that they can enjoy their own private island in a tropical paradise, with fast internet, easy travel, and friendly locals. Emphasize the advantages that they can enjoy right now, with no change.
In the long term, pitch them on the idea that they can help grow a community that will gradually shift the government in a libertarian direction. Note that once the community is large enough, it will have the clout to successfully lobby for more liberal immigration laws, a special economic zone for seasteads, lower tariffs/taxes. Changes that will be likely seen as mostly innocuous, but will attract more like minded people.
With luck, over time, the community will grow large enough that they will real clout in the government, and they can advocate for more radical changes, such as full drug legalization, replacement of the local currency with bitcoin, etc.
Or maybe don't even try to effect such changes on land (as they would likely trigger the immune response). Just ask that San Bastiat to be left alone to grow without molestation.
At 40,000, the community would have the same population as Monaco or Lichtenstein. That's only seven cruise ships worth of people. At 120,000, the population would be in the same ballpark as Aruba, Tonga, or Curacao, or 24 cruise ships.
At that point, the community would be too big for the US or Panamanian authorities to easily quash, since killing or imprisoning the residents would draw international media attention. At that point, leaving the community alone may well be less costly to the governments of the world than suppressing it.
And if they do try to kill you, at least you'll have several other countries nearby you could flee to.