I've essentially never seen anything from the sphere of "parapolitics" that actually appears to impart any useful practical knowledge for understanding the past or predicting the future, at best it appears to be a masturbatory hobby that lets you be smug about JFK for 50+ years straight, at worst it makes you some annoying asshole who goes around saying shit like "denying the existence of snuff films is leftist flat earth" for attention.
Also Programmed To Kill is a very stupid book.
It seems fine as it's own work, just sorta comes off like a separate work of fiction that had to be stapled onto the Watchmen IP instead of being its own thing.
Like the whole Hooded Justice thing isn't bad, but I think it kind of fails to exploit what Moore was going for by making the "first" costumed superhero in his universe a nazi-sympathizing sadist dressed up in thinly veiled lynching iconography and a dark klan hood.