Don Wollheim also reprinted the Ole Doc Methusaleh stories, which were not Hubbards best by any means.
But I agree - if not for Dianetics, I suspect a lot more of Hubbard would have been reprinted. I read all the Golden Age Astoundings from the MITSFS collection, and IIRC Hubbard got pretty good AnLab scores and lots of covers. I have most of the run of Unknown. Those who criticize his writing really should read him in the context of the writers of the day. I’d say he was far better than average. Final Blackout was a very dark after the Bomb story written before the bomb. I think it couldn’t have been published after we joined the war for being too much of a downer. (No, there was no bomb in it - Europe destroyed themselves with non-nuclear weapons.) It wasn’t the first such story - the sequence in “Things to Come” was similar, but it was pretty powerful.
LOL I read all ten books as part of a library contest in high school (I won, and got a gift certificate, which I spent on an even longer book series (Robotech). I however, being probably the only person on Earth who can say this, actually rather enjoyed them.
The page you referenced, Summary Bibliography: L. Ron Hubbard , lists what we call “titles”, i.e. novels, collections, stories and other SF&F and SF&F-related texts. If you want to see all editions (or “publications”, as we call them) for a particular title, you have to follow that title’s link. For Slaves of Sleep it’s Title: Slaves of Sleep and it shows the Lancer reprint (Publication: Slaves of Sleep) that you mentioned.