The author has existed online since at least 2011, so it wouldn't surprise me that he has just accumulated posts over time and migrated them, maybe haphazardly,

The author has existed online since at least 2011, so it wouldn't surprise me that he has just accumulated posts over time and migrated them, maybe haphazardly, to new installations. He's reader-funded which would explain what looks like some lost domain registrations over the years.