That doesn't really look that they're really "independent from the State". Even if they only went on shore to buy necessary goods and paid necessary services like medical emergency treatment with their own money, they are using a State's infrastructure, like roads, ports etc.
I'm sorry, I think seasteading doesn't have a future if it's not carried out with LOTs of planning, and preferably by a major group of people. Anarchy isn't only about "not paying taxes". It has also to do also with finding alternatives for the services states provide to you.
the trouble with that mindset is that
somebody has to do
something first, even if it's one step in a series of incremental steps. if the Thai government hadn't acted this way, there was a possibility of taking further steps. Your criticism seems to be that Elwar didn't execute every possible detail from the beginning, that's unrealistic for many reasons. taking the simplest foundational steps first at least means something actually happened, instead of endless talking about it
Elwar was the first to try. Maybe we could argue that he should have seen this coming, but he deserves alot of respect for at least trying, and it was no insignificant attempt. He spent alot of money & time planning and contructing his seastead, which is more than most people in the seasteading bracket have done