>Why do I like this concept? Simple - it's classic early
>sci-fi. Victorian SF writers, especially, loved to present their
>works as "memoirs" of witnesses to "actual events", as did H.P.
>Lovecraft.

I can only imagine what horrors envisioned by the good Mr. Lovecraft exist in the UF universe. Randolph Carter has appeared, along with mentions of his own adventures, but that's fairly tame compared to, say, Dr. Herbert West.