I’m running Connect and it’s pretty great. On every post I can block instance, community, or user. For comments, you can view user, then click a link to their instance (looks like a overview/summary page) and there’s an option to block instance there.
There’s also a general settings option in the sidenav where you can type in an instance name or community to block it if you already know the name, or remove ones from your blacklist if you change your mind.
Connect has been a great experience. I only put up with the default client for like 1 day because I hated it.