Still thinking about what radically different things my ideal social media / microblogging platform would do, and another thing struck me: no @-mentions. No need to protect someone's mentions if there are none.

Yes, I'm still on my Tumblr-like vs Twitter-like thing and how within ActivityPub platforms we have loads of the latter and none of the former (that I know of). I don't know whether Tumblr has since added @-mentions but back when I used it they weren't a thing and I loved how this made conversations impossible. No trolls etc demanding attention in a thread that everybody is exposed to, if there is no thread.

I'm thinking of have these interaction options: you post your microblog post and indicate whether you want replies, default no. Followers and profile visitors see the post and can respond with a like, a reblog on their own profile, or a reblog on their own profile with added text. They can also reply privately to you, which won't show up publicly attached to the post (yet). You have three tabs for incoming replies: replies you asked for (which cause a notification), replies from people you follow (optionally cause a notification), replies you didn't ask for from people you don't follow (never cause a notification or unread count or badge). If you like a reply, if you even see it, you can hit a button to promote it to your microblog, seen on your profile, possibly attached to the post.