As far as I know you can tag any label you want to posts in ATProto even if the AppView doesn't support it or you need to subscribe to a custom labeler in order to see it, but I haven't really looked into it.
But yeah, the Fedi CW system is great and it annoys me how so many people on Bluesky hate the idea of it because of the mythical CW police that either didn't exist in the first place or already moved off the platform over to Bluesky to be insufferable in new and unique ways over there.