The most prolific self-references I found were UUCP maps updates because I ran a node which was in the centrally coordinated catalog (iirc it drove honey-danber to convert a!b!c paths to user@c so you didn't have to hand-route)
The second-most prolific self references were blovating across all and any groups I felt like. Nothing has changed.
Oh my god this is a lifesaver. Just last week I was using Google Groups to search for old Usenet posts about the Commodore 64 and the Mimic Spartan, and I was getting "too many requests" errors 4 out of 5 times clicking a result. Happened on VPN+incognito, and in a separate browser. Just searched for what I was looking for in Rewind and immediately found the posts and even some I never saw in Google Groups results. So glad all of this is archived in multiple, non Google places
Not to be a party pooper but this is a paid service. I am sure there are reasons to pay but I bet their archive is the same as https://usenet.blueworldhosting.com which is free. A free web frontend can be found at https://newsgrouper.org
The second-most prolific self references were blovating across all and any groups I felt like. Nothing has changed.