I think the Candid alias, and the No Narrative, No Plot, and No Story trio should be split off from the Gonzo tag.
Currently, the Gonzo tag is described as
Does not have any type of narrative, with performers simply playing themselves.
Merriam-Webster defines Gonzo as:
1
: of, relating to, or being a style of journalism marked by a lack of objectivity due to the writer’s immersion in the subject and often participation in the activity being documented
gonzo journalism
a gonzo journalist2 informal
a : outlandishly unconventional, outrageous, or extreme
a gonzo comedianb : very strange or unusual : bizarre
gonzo notions
Wikipedia defines “Gonzo pornography” even better:
Gonzo pornography is a style of pornographic film that attempts to place the viewer directly into the scene. …
The name is a reference to gonzo journalism, in which the reporter is part of the event taking place. By comparison, gonzo pornography puts the camera right into the action, often with one or more of the participants filming and performing sexual acts, without the usual separation between camera and performers seen in conventional porn and cinema.
Gonzo porn is influenced by amateur pornography, and it tends to use far fewer full-body/wide shots in favor of more close-ups and heavy use of wider angle lenses (see: reality pornography). The loose and direct camera work often includes tight shots of the genitalia, unlike some traditional porn.
Conversely, Candid is defined by Merriam-Webster as
3 : relating to or being photography of one or more subjects acting naturally or spontaneously without being posed
candid photos of the family at play
I think there’s some overlap between Candid and Gonzo, or, perhaps, Gonzo is a subset of Candid. For example, a glamour studio’s Candid is definitely not Gonzo. (Are all Gonzo scenes Candid? 
)
As for No Narrative, No Plot, and No Story, they might be a superset of Candid and Gonzo but I think they’re another separate entity. The great gonzo journalists (like Hunter S. Thompson) definitely had narrative though they might’ve had no plot. I can’t imagine that porn studios are discerning enough to differentiate between these three tags so I think it’s safe to lump these together.