Random thought: on some websites I've been to, muting a person doesn't make their posts invisible, it just makes them where you always have to click them to read them.
I wonder how a "half-mute" feature would be received, where a user can say "put all posts from this user behind a client-side CW". This would help for following people who regularly post things that wouldn't be CW-worthy by the norms of their instance.
Other thoughts for this setting I call "shielding":
* Shield all toots from this person
* Shield all toots on this instance
* Shield all toots from users on remote instances I don't follow