Yes, they are. But the definition of Outbox keeps growing and there is no definition on how many of these strategies a client must implement in order to be called outbox compliant.
I'd say Amethyst is 30% there.
Discussion
Does Amethyst keep track about the relay usage of users and does it use this information to find notes and tag users?
Technically not. But we are starting to have something like that. Last version only asked for notes from the Outbox relay of each author.
30% is good enough for me to keep on the list. maybe ill rephrase the wording a bit.