As far as seasteading projects or startup societies in general go, Atlas Island seems to be the most promising only because their site doesn't include any third-party scripts.
They have a Telegram but they mostly communicate via email.
Concept: A bunch of packet radio nodes that sync messages with each other. So you can write a message on one node and it (eventually) gets put on all of them - kind of like a packet BBS except over a much larger range, and distributed