For examples, Shattrath/outland, Oribos/shadowlands, Iskaara or Valdrakken/dragonflight.

Current checkbox options address foe and friend, but non-friend isn't Foe in this case so they get "plain" names over their heads.

I know, but don't really understand, how there are "names" over players, and "plates" over them. Ideally there should be some way to see proper plates for non-hostile Players.

This may be able to piggyback on or share code with another issue about wanting to not see players in Sanctuaries.

As it currently stands a threatplate kit that silences almost all nameplate traits doesn't shush these non-plated people.

Maybe you can look into this: #353. It disables friendly nameplates when in a city, but might be adaptable.