I know that posts can be hidden by reading.
But what I miss most is a button to hide posts while scrolling over them, so that I don’t see the same posts over and over again.
(Boost for Reddit has a Button to “hide all previous”, so you don’t have to hide each post individually, but all at once)
Relay had the option to “mark as read” on scrolling and a separate option to “mark as read” on individual posts along with the option to clear read items from the currently displayed list, very handy if you wanted to clear stuff you weren’t interested in while keeping the list populated with posts you might want to go back to.