FWIW I think the late Dan Kaminsky is the person who originally invented this two process userspace TCP scan technique 2001-2002ish in his tool Paketto Keiretsu.

It's a good one.

I sometimes wonder if it inspired some of the TCP-in-userspace stuff that is done in go (gvisor lib, I think it was).

I'm glad Rob is continuing the development of this idea and continues to scan the whole internet. Scanning the whole internet is cool. It's a shame it's de facto illegal these days (and will get most internet connections in the USA terminated near-instantly).