I have an account on lemmynsfw and pornlemmy. When I view all on the pornlemmy account it only shows NSFW, although I find that instance to be a bit iffy in terms of availability. Lemmynsfw is larger and more stable, but when I view all it includes SFW stuff as well.
Not sure if there's a way to choose to filter like that at will or if it can only be set at the instance level, but I would love to know if it can be done as well.
The point is that we want to see all NSFW across all instances. Local is only going to show NSFW posts from whatever instance you're in, which is not the goal here.