I haven't heard of any real progress from seasteading for a long time now, and it doesn't seem that they necessarily support libertarian islands, nor does it seem that their business strategy (which doesn't seek investment from commercial companies that want tax heavens) is a smart one.
Are you aware of any other plans to create artificial libertarian islands?
They recently got that ship Seasteading I. But overall, I do not expect too much progress from seasteding. I am fallible, though, so who knows? They might be awesome.