Switches, radios and boxes that save the moment you use them keep the keyboard’s focus while they save, in the app and the console. When a list’s last page takes Show more away, the focus goes to the first row it brought. Report’s choices grow with your text size, a profile card’s ⋮ is drawn whole, and the website’s pages show the same focus ring as the app.
Activity shows a reaction to your message, a keyword you follow and an invitation to a Link the moment it arrives, as it already did for mentions, direct messages and replies.